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Full text of "Studies in the morphology, taxonomy, and ecology of the Peridiniales"

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LYRASIS Members and Sloan Foundation 



http://archive.org/details/studiesinmorpholOOcarn 



DEPARTMENT OF TERRESTRIAL MAGNETISM 

J. A. Fleming, Director 



Scientific Results of Cruise VII of the CARNEGIE during 1928-1929 

under Command of Captain J. P. Ault 



BIOLOGY- III 



Studies in the Morphology, Taxonomy, 
and Ecology of the Peridiniales 



HERBERT W. GRAHAM 




CARNEGIE INSTITUTION OF WASHINGTON PUBLICATION 542 

WASHINGTON, D. C. 

1942 



ear. terrestrial magt*£t<skj 
CARNEGIE INSTITUTION 

WASHINGTON. D.& 

3CJ3J' 



This book first issued September 23, 1942 



PREFACE 



Of the 110,000 nautical miles planned for the seventh 
cruise of the nonmagnetic ship Carnegie of the Carnegie 
Institution of Washington, nearly one-half had been com- 
pleted upon her arrival at Apia, November 28, 1929. The 
extensive program of observation in terrestrial magnet- 
ism, terrestrial electricity, chemical oceanography, 
physical oceanography, marine biology, and marine me- 
teorology was being carried out in virtually every detail. 
Practical techniques and instrumental appliances for 
oceanographic work on a sailing vessel had been most 
successfully developed by Captain J. P. Ault, master and 
chief of the scientific personnel, and his colleagues. The 
high standards established under the energetic and re- 
sourceful leadership of Dr. Louis A. Bauer and his co- 
workers were maintained, and the achievements which 
had marked the previous work of the Carnegie extended. 

But this cruise was tragically the last of the seven 
great adventures represented by the world cruises of the 
vessel. Early in the afternoon of November 29, 1929, 
while she was in the harbor at Apia completing the stor- 
age of 2000 gallons of gasoline, there was an explosion 
as a result of which Captain Ault and cabin boy Anthony 
Kolar lost their lives, five officers and seamen were in- 
jured, and the vessel with all her equipment was de- 
stroyed. 

In 376 days at sea nearly 45,000 nautical miles had 
been covered (see map on p. v). In addition to the ex- 
tensive magnetic and atmospheric-electric observations, 
a great number of data and marine collections had been 
obtained in the fields of chemistry, physics, and biology, 
including bottom samples and depth determinations. 
These observations were made at 162 stations, at an av- 
erage distance apart of 300 nautical miles. The distri- 
bution of these stations is shown in map, which deline- 
ates also the course followed by the vessel from Wash- 
ington, May 1, 1928, to Apia, November 28, 1929. At 
each station, salinities and temperatures were obtained 
at depths of 0, 5, 25, 50, 75, 100, 200, 300, 400, 500, 700, 
1000, 1500, etc., meters, down to the bottom or to a max- 
imum of 6000 meters, and complete physical and chemi- 
cal determinations were made. Biological samples to 
the number of 1014 were obtained both by net and by 
pump, usually at 0, 50, and 100 meters. Numerous phys- 
ical and chemical data were obtained at the surface. 
Sonic depths were determined at 1500 points and bottom 
samples were obtained at 87 points. Since, in accordance 
with the established policy of the Department of Terres- 
trial Magnetism, all observational data and materials 
were forwarded regularly to Washington from each port 
of call, the records of only one observation were lost 
with the ship, namely, a depth determination on the short 
leg from Pago Pago and Apia. 

The compilations of, and reports on, the scientific 
results obtained during this last cruise of the Carnegie 
are being published under the classifications Physical 
Oceanography, Chemical Oceanography, Meteorology, 
and Biology, in a series numbered, under each subject I, 
II, III, etc. 

A general account of the expedition has been prepared 
and published by J. Harland Paul, ship's surgeon and ob- 
server, under the title The last cruise of the Carnegie, 
and contains a brief chapter on the previous cruises of 
the Carnegie, a description of the vessel and her equip- 
ment, and a full narrative of the cruise (Baltimore, Wil- 
liams and Wilkins Company, 1932; xiii + 331 pages with 



198 illustrations). 

The preparations for, and the realization of, the pro- 
gram would have been impossible without the generous 
cooperation, expert advice, and contributions of special 
equipment and books received on all sides from inter- 
ested organizations and investigators both in America 
and in Europe. Among these, the Carnegie Institution of 
Washington is indebted to the following: the United States 
Navy Department, including particularly its Hydrographic 
Office and Naval Research Laboratory; the Signal Corps 
and the Air Corps of the War Department; the National 
Museum, the Bureau of Fisheries, the Weather Bureau, 
the Coast Guard, and the Coast and Geodetic Survey; the 
Scripps Institution of Oceanography of the University of 
California; the Museum of Comparative Zoology of Har- 
vard University; the School of Geography of Clark Uni- 
versity; the American Radio Relay League; the Geophys- 
ical Institute, Bergen, Norway; the Marine Biological 
Association of the United Kingdom, Plymouth, England; 
the German Atlantic Expedition of the Meteor . Institut 
fur Meereskunde, Berlin, Germany; the British Admiral- 
ty, London, England; the Carlsberg Laboratorium, Bu- 
reau International pour l'Exploration de la Mer, and 
Laboratoire Hydrographique, Copenhagen, Denmark; and 
many others. Dr. H. U. Sverdrup, now Director of the 
Scripps Institution of Oceanography of the University of 
California, at La Jolla, California, who was then a Re- 
search Associate of the Carnegie Institution of Washing- 
ton at the Geophysical Institute at Bergen, Norway, was 
consulting oceanographer and physicist. 

In summarizing an enterprise such as the magnetic, 
electric, and oceanographic surveys of the Carnegie and 
of her predecessor the Galilee , which covered a quar- 
ter of a century, and which required cooperative effort 
and unselfish interest on the part of many skilled scien- 
tists, it is impossible to allocate full and appropriate 
credit. Captain W. J. Peters laid the broad foundation of 
the work during the early cruises of both vessels, and 
Captain J. P. Ault, who had had the good fortune to serve 
under him, continued and developed that which Captain 
Peters had so well begun. The original plan of the work 
was envisioned by L. A. Bauer, the first Director of the 
Department of Terrestrial Magnetism, Carnegie Institu- 
tion of Washington; the development of suitable methods 
and apparatus was the result of the painstaking efforts of 
his co-workers at Washington. Truly, as was stated by 
Captain Ault in an address during the commemorative 
exercies held on board the Carnegie in San Francisco, 
August 26, 1929, "The story of individual endeavor and 
enterprise, of invention and accomplishment, cannot be 
told." 

Dr. H. W. Graham, who succeeded H. R. Seiwell as 
chemist and biologist, had charge of the biological work 
on board the Carnegie from August, 1929, until the loss 
of the vessel at Apia, Samoa. After his return to this 
country, Dr. Graham was placed in charge of the biolog- 
ical collections, attending to their subsequent care, se- 
gregation, and distribution to various specialists for ex- 
amination and report, he himself undertaking the not in- 
considerable task of reporting upon the Peridineae 
(Dinoflagellata). 

Except for the Family Ceratocoryaceae (consisting 
of one genus, seven species) and the Family Goniodoma- 
ceae (one monotypic genus), which have been more or 
less monographically treated in their entirety, this paper 



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PREFACE 



is but preliminary to a report on the Peridiniales col- 
lected during the last cruise of the Carnegie . Otherwise, 
only certain species of three other families (Peridinia- 
ceae, Gonyaulaceae. Ceratiaceae) of the fourteen fami- 
lies into which the order is subdivided are dealt with. 
However, Dr. Graham's studies are of fundamental im- 
portance to any adequate understanding of the structure 
and relationships of the species and higher categories of 
the Peridiniales. These studies were undertaken with 
that particular purpose in mind. His discussion of the 
selected species is well illustrated and gratifyingly com- 
plete. 



Further details regarding the procedure followed in 
making the tow-net hauls at the various oceanographic 
stations are given in the first volume of the Biological 
Reports of this series, "The copepods of the plankton 
gathered during the last cruise of the Carnegie , ' ' by 
Charles Branch Wilson (1942). 

This manuscript was completed by Dr. Graham in 
1938. Thus some papers printed since then are not con 
sidered. 

J. A. Fleming 
Director, Department of Terrestrial Magnetism 



CONTENTS 



Abstract 

Introduction 

General Discussion . . . 
Material and Methods 



Page 
1 
. 2 
. 3 
. 3 



Survey of the Order Peridiniales 4 

General Statements 4 

Families 4 

Genera 5 

State of Knowledge of Morphology 5 

Forms Treated in This Report 6 

Relationships among the Genera 6 

General Considerations 6 

Ventral Area 7 

Girdle 9 

Hypotheca 9 

Epitheca 9 

Summary 9 

Systematic Discussion 11 

Family Peridiniaceae 11 

Genus Peridinium 11 

P. depressum Bailey and Related Forms . 15 

P. depressum 18 

P. depressum var. parallelum 21 

P. depressum var. rectius 22 

P. depressum var. convexius 23 

P. depressum f. bisintercalares .... 23 

P. depressum f. multitabulatum 23 

P. claudicanoides 24 

P. oceanicum 24 

P. oceanicum var. tenellum 25 

P. oceanicum f. spiniferum 26 

P. oceanicum f. bisintercalares 26 

P. oceanicum f. tricornutum 27 



Page 

P. crassipes 27 

P. truncatum 30 

P. truncatum forma acutum 32 

P. pallidum 32 

Family Ceratocoryaceae 34 

Genus Ceratocorys 34 

Subgenus Euceratocorys 38 

C horrida 38 

C. armata 40 

C. reticulata 42 

C. aultii 42 

C. bipes 43 

Subgenus Protoceratocorys 43 

C. skogsbergii 44 

C. gourretii 44 

Family Goniodomaceae 45 

Genus Goniodoma 45 

G. polyedricum 46 

Family Gonyaulacaceae 47 

Genus Gonyaulax 47 

G. pacifica 48 

G. fusiformis 50 

Genus Acanthogonyaulax 52 

A. spinifera 53 

Genus Spiraulax 54 

S. kofoidii 55 

Family Ceratiaceae 56 

Genus Ceratium 56 

C. pavillardii 56 

Tables 59 

Bibliography 91 

Figures 95 

Index 129 



vii 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



By Herbert William Graham 



Abstract 



Although the Peridineae (Dinoflagellata) have been 
rather extensively studied, there is still very little 
known about many aspects of this interesting group of 
the Protista. The purpose of this paper is to contribute 
to our knowledge of the morphology, taxonomy, and ecol- 
ogy of this group. 

It was the author's privilege to have the opportunity 
to study the Peridineae of the plankton samples collect- 
ed on the last world cruise of the nonmagnetic research 
vessel Carnegie of the Department of Terrestrial Mag- 
netism, Carnegie Institution of Washington. The exten- 
sive nature of this collection not only permitted a de- 
tailed taxonomic analysis of a large variety of species, 
but also afforded a good opportunity to make a study of 
the geographic distribution of these forms throughout 
the Pacific and North Atlantic oceans, based on compar- 
able material. The simultaneous collecting of biologi- 
cal samples and hydrographic data also offered a rare 
opportunity to correlate the established distributions 
with oceanographic conditions. 

The present paper deals with twenty-nine repre- 
sentatives of the order Peridiniales. They are distrib- 
uted among the families of the order as follows: one in 
Goniodomaceae; seven in Ceratocoryaceae; four in Gon- 
yaulacaceae; sixteen in Peridiniaceae; and one in Cer- 
atiaceae. They include six new species, three new vari- 
eties, and six new forms. Two old specific names were 
replaced and one subgenus raised to the rank of genus. 
A monographic treatment was given all the species 
(seven) of the family Ceratocoryaceae. 

The species selected were subjected to a morpho- 
logical analysis with the following objects in mind: (1) 
to establish a standard for the analysis and recording 
of the skeletal features of peridinian species; (2) to ac- 
quire a knowledge of the detailed skeletal morphology 
of certain species; (3) to study variation within the 
group by subjecting a few forms to intensive analysis; 
and (4) to contribute to the concepts of the relationships 
of the genera of the peridiniales. In addition to this 
morphological and taxonomic treatment, each species 
was studied from the standpoint of geographic distribu- 
tion and relationships to the following hydrographic 
conditions: temperature, salinity, hydrogen-ion concen- 
tration, and phosphate content. 

Much of the confusion among systematists in the 
past regarding the Peridineae has been due to inade- 
quate descriptions and figures. Since type specimens of 
peridinians usually cannot be preserved, it is impera- 
tive that the descriptions and figures of the species be 
not only complete but standard in nature so that ade- 
quate comparisons with other material can be made. 
Standard methods of measurement and of expression of 
body shape were introduced in the case of each genus 
studied. 

The skeletal features of the forms treated were 
very carefully analyzed by microdissection. Particular 
attention was given the ventral area, a region of the 
theca of the Peridiniales which was almost unknown be- 
fore these investigations. A great diversity in the 
structure of the ventral areas of the various genera was 
found, although a common basic plan was evident. The 



area is composed of from five to seven external plates 
and, sometimes, one internal plate. A nomenclature 
was devised for these plates which would serve to iden- 
tify them and at the same time express homologies. 

In some families of the Peridineae, species are 
well defined and there is comparatively little difficulty 
in determining them. In other groups, however,. specific 
variability is so striking that no investigator has yet 
attempted a comprehensive taxonomic treatment. In the 
Peridiniaceae, for instance, the plate pattern is so var- 
iable that it cannot be successfully used for the differ- 
entiation of genera, and the body shape so variable that 
all attempts at specific segregation have failed. For this 
reason, a statistical method was applied to certain rep- 
resentatives of Peridinium in order to determine its 
efficacy in the delimitation of species. A large number 
of specimens was measured; the body shapes were ex- 
pressed numerically; and the frequency of the various 
shapes was plotted. By this method groupings were ob- 
tained which indicated the delimitation of species and at 
the same time demonstrated the range of variation of 
each species. 

On the basis of the comparative study of the ventral 
areas of the various genera it was concluded that Goni- 
odoma is the most primitive genus; that Ceratocorys is 
closely related to Goniodoma but somewhat more ad- 
vanced; that Gonyaulax , Acanthogonyaulax , and Spiraulax 
are decidedly more advanced and in addition are closely 
related to each other; and that the genera Peridinium 
and Ceratium are highly specialized and, although relat- 
ed, are developed along divergent lines. The compari- 
sons of the girdle, hypotheca, and epithecal plates of 
these genera corroborate the conclusions arrived at 
from the study of the ventral area itself although these 
results could not have been obtained by the study of 
these last series of plates alone. 

Some of the marine peridinians are useful in trac- 
ing the movements of oceanic water masses. The dis- 
tributions of the species treated in this report were ex- 
amined in relation to hydrographic conditions in order 
to ascertain the value of each species as an oceano- 
graphic "indicator." Of the species treated, Ceratoco - 
rys horrida and Goniodoma polyedricum were found to 
be the most valuable indicators of hydrographic condi- 
tions. Their distributions are closely correlated with 
the temperature of the water and the species are suffi- 
ciently common to make negative records of occurrence 
significant. 

Ceratocorys horrida was found throughout the trop- 
ics and warm-temperate regions. Its limits of distrib- 
ution were sharply marked and these limits coincided 
with the 19° C isotherm. Thus, in an intensive oceano- 
graphic investigation, an occasional record of this spe- 
cies in water with temperature less than 19° would in- 
dicate an intrusion of tropical water or of water mixed 
with water of tropical origin. 

Goniodoma polyedricum , on the other hand, is a very 
common tropical species which can endure transfer into 
regions of much cooler water. It occurred at practical- 
ly all the Carnegie tropical stations (where the temper- 
atures ranged from 20 to 30° C). It was carried into 



1 



INTRODUCTION 



water with temperatures as low as 15° and i6° C off 
Japan, off California, and in the southeastern Pacific. 
In the Atlantic it was found near the British Isles in wa- 
ter with temperatures as low as 12 °4 C. It was un- 
doubtedly carried there in the North Atlantic West Wind 
Drift. Thus, this species is an excellent indicator of 
the intrusions of tropical water masses. 

It was a notable fact that while the temperature 
conditions appeared to regulate the distribution of many 
species, no correlations could be found between the 
chemical composition of the water and these distribu- 
tions. The most striking result obtained in regard to 
the relation between the chemical conditions and specif- 
ic distributions was that some photosynthetic species 



thrive equally well in water extremely poor in phos- 
phate and in richer waters. The upper levels of vast 
areas of the middle North Pacific are practically de- 
void of phosphate. The concentration of phosphate ion 
is less than 10 mg/m 3 , i.e., less than 10 parts of phos- 
phate per billion parts of water. In the case of many 
species studied, this area of low nutrient content was 
not in any measure a barrier to distribution. Thus, it 
is apparent that these species of peridinians can utilize 
extremely low concentrations of nutrient salts. This 
phenomenon is undoubtedly correlated with the normal 
seasonal appearance of peridinians following the diatom 
outbursts of northern waters during the spring and fall. 



INTRODUCTION 



In 1928 the Department of Terrestrial Magnetism 
of the Carnegie Institution of Washington sent out its 
nonmagnetic ship Carnegie on a world cruise of all the 
major oceans exclusive of the Arctic. In addition to the 
investigations of earth magnetism there was conducted 
a program of oceanographic investigations. This pro- 
gram included the collection of plankton samples and the 
determination of hydrographic conditions at regular in- 
tervals. Unfortunately, the cruise was brought to an 
untimely end by the destruction of the vessel before it 
had visited the Indian and Antarctic oceans. However, 
162 stations were occupied over extensive areas of the 
Pacific and North Atlantic oceans. In 1929 the author 
was placed in charge of the biological work on board, 
and at the termination of the cruise he was given charge 
of the biological collections. 

The extensive nature of the collections permitted, 
not only a detailed taxonomic analysis, but also a study 
of geographic distribution based on comparable materi- 
al. The simultaneous collecting of biological samples 
and hydrographic data also offered a rare opportunity to 
study the relations between the pelagic organisms and 
their environmental conditions. 

After certain general quantitative studies of the 
plankton were made, a study was begun which would lead 
to a general knowledge of the plankton communities in 
the various regions and to a knowledge of the relation of 
the individual planktons to each other and to environmen- 
tal conditions. As a foundation for this it was necessary 
first to compile lists of the species occurring at each 
station. 

As a preliminary to this program the organisms in 
the -samples were sorted according to groups and each 
group was submitted to a systematist for identification 
and analysis. The author selected the Peridineae (Dino- 
flagellata) for his own special study. 

These introductory remarks have been made in or- 
der to give some idea of the origin of the material and 
of the general scientific inquiry of which this report 
forms a part. The discussion that follows is restricted 
entirely to the peridinians. 

It was originally planned to make a comprehensive 
study of this group in the Carnegie collection mainly 
from the standpoint of geographic distribution and ecol- 
ogy. A floristic treatment, naturally, would be the foun- 



dation for such a study. The analysis, however, was not 
far advanced before it was realized that no thorough and 
certain floristic treatment of the Peridineae was possi- 
ble in the present state of the taxonomy of the group. It 
was found that not a single genus of the group was cov- 
ered by an exhaustive monograph which would enable 
one to make identifications of the species with any de- 
gree of certainty. As a consequence, the floristic anal- 
ysis had to be preceded by a thoroughgoing taxonomic 
study. 

The present paper deals with a small part of the 
peridinian problem of the Carnegie material. It pertains 
to certain forms of the order Peridiniales which were 
selected for study and subjected to a careful morpholog- 
ical analysis with the three following objects in mind: 
(1) to establish a standard for the analysis and the re- 
cording of the morphology of peridinian species; (2) to 
acquire a knowledge of the detailed skeletal morphology 
of some of the species; (3) to study variation within the 
group by subjecting a few forms to intensive analysis; 
and (4) to contribute to the concepts of the relationships 
of the genera of the Peridiniales. 

The Carnegie material afforded interesting compar- 
ative material because it contained not only rare tropi- 
cal forms, but also temperate and subpolar material 
from widely separated regions. 

Assistance in the routine census of the samples and 
in the preparation of preliminary camera lucida sketch- 
es was given by Mrs. N. Bronikovsky. Most of the fin- 
ished ink drawings and wash drawings were executed by 
Mr. Charles A. Dawson. The investigations were car- 
ried out at the Hopkins Marine Station, Pacific Grove, 
California through the courtesy of Dr. W. K. Fisher, Di- 
rector. Valuable critical advice was received through- 
out the investigations from Dr. Tage Skogsberg, under 
whose direction the work progressed. The pursuance of 
the investigations was made possible through the good 
offices of Dr. J. A. Fleming, Director of the Department 
of Terrestrial Magnetism of the Carnegie Institution of 
Washington, who has been in charge of the oceanograph- 
ic program of the Carnegie and who has lent his contin- 
uous interest and support to the biological work. To all 
these I wish to express my deep appreciation for their 
sympathetic assistance in the furtherance of the work. 



GENERAL DISCUSSION 



MATERIAL AND METHODS 



During the Carnegie expedition 162 "oceanographic 
stations" and 69 "surface plankton stations" were oc- 
cupied. The collecting program at each "oceanograph- 
ic station" included the towing of a 1 meter plankton net 
at the surface, and of 1/2 meter nets at 50- and 100- 
meter depths. The upper half of the nets was construct- 
ed of no. 10, the lower half of no. 15 silk bolting cloth. 
The nets were towed for 1 hour. At the "oceanographic 
stations," from station 11 on, duplicate quantitative 
samples were taken with a Pettersson plankton pump. 
At the "surface plankton stations" various types of silk 
nets were used depending on the speed of the vessel, and 
they were towed for different lengths of time. 

Only open nets were used. This introduced a pos- 
sibility of error in the census of the subsurface sam- 
ples. This error, however, was not great as the length 
of time the nets were towed at their respective depths 
(1 hour) was so much greater than the length of time 
required for raising the net (about 2 minutes). Thus, 
unless there was a very pronounced density of popula- 
tion in an upper stratum, the proportion of upper-level 
organisms to the standard- level organisms would be 
very low. The comparison of the hauls from the three 
levels would reveal this. 

It should be noted that all collections outside the 
tropics were made in the summer time. The cruise was 
planned so that the vessel would be in the higher lati- 
tudes of each hemisphere in its respective summer in 
order to avoid too rough weather. For that reason, the 
distributional records show no winter records outside 
the tropics. 

The plankton samples were preserved and stored 
in formalin. In the laboratory the peridinian material 
was treated with a solution of hypochlorite, from 10 to 
50 per cent, according to the nature of the material as 
established by experience. This reagent was applied in 
order to dissolve the cell contents and to weaken the 
thecal sutures so that the plates could be readily sepa- 
rated. In some instances it caused a swelling of the 
protoplast followed by premature rupture of the theca. 
For this reason, drawings were made of the specimen 
in various views with as much detail as could be made 
out before the hypochlorite treatment. In cases where 
there was ample material, portions of unsorted sample 
were given the hypochlorite treatment, but where the 
material was rare, single specimens were transferred 
with a micropipette. 

After the treatment with hypochlorite for a varying 
length of time, depending on the material, the specimens 
were washed in water and, in some cases, stained with 
trypan blue. Specimens with oil droplets, such as Peri - 
dinlum depressum. were cleared with xylol in order to 
dissolve the oil, which interfered with proper staining. 
The specimen thus treated for study was transferred to 
a warm flat drop of glycerin jelly by means of a micro- 
pipette and examined without a cover glass. In this me 
dium the specimen could be oriented to any desired po- 
sition, and, after the jelly cooled to room temperature 



and hardened, the specimen was in a solid medium and 
a camera lucida drawing could be made. After obser- 
vation and drawing in one view, the jelly could be melt- 
ed and the specimen reoriented any number of times. 
The glycerin jelly was softened by placing it on a warm- 
ing table heated to a temperature of 50° C. During 
periods of warming, the drop was covered with a small 
damp chamber to prevent undue evaporation of water 
and consequent troublesome thickening of the jelly. The 
specimen was manipulated by means of a micro-needle 
prepared by mounting a piece of spun glass from a 
glass-wool filter on the end of an ordinary dissecting 
needle. The glass hair projected about 3 millimeters 
beyond the point of the steel needle. As it became 
clogged with jelly, it was trimmed with scissors until 
about 1 millimeter long, when it was replaced. 

The melting point of the glycerin jelly can be con- 
trolled by varying the water content. All the water was 
never allowed to evaporate on the warming table, how- 
ever, as the jelly then had a tendency to become sticky 
even though more water was added. The solution of jel- 
ly kept on the warming table for the preparation of 
slides was at all times covered, and water was added 
occasionally to compensate for evaporation. 

This method proved satisfactory for studying the 
specimens in various positions without injuring them. 
It is impossible to orient some material, for instance 
Peridinium depressum, by rolling a specimen in a water 
mount under a cover glass, because of the unbalanced 
nature of the theca in all but four positions, none of 
which is particularly desirable for descriptive purposes. 
The above method also afforded a satisfactory means of 
dissecting. A specimen which has been properly cleaned 
in hypochlorite will begin to break apart in a glycerin- 
jelly mount when pressure is applied with the glass hair 
or when it is gently touched with a fine steel needle. 
When the plates have begun to separate, an individual 
plate or group of plates may be selected and oriented to 
any desired position by stroking the surrounding jelly 
with the glass hair, without danger of crushing or losing 
the rest of the specimen. For the examination of details 
like pores, when it is necessary to use an oil-immersion 
objective, it is usually advisable to mount under a cover 
glass in glycerin jelly, water, or balsam. 

All drawings were made with the aid of a camera 
lucida. In some cases they were later enlarged to facil- 
itate shading. 

Owing to the pronounced asymmetry of the body of 
some of the forms, they presented quite different pro- 
files in different positions. Thus, the measurement of 
any contour may vary considerably even though the po- 
sition of the body is changed but slightly. For this rea- 
son it is necessary to adopt standard positions for mak- 
ing measurements. In the present work the ventral view 
has been adopted for the principal standard position. 
There is some difficulty in determining the "ventral 
view" in some of the more asymmetrical forms, partic- 
ularly in species of Peridinium with long horns. In such 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



forms it is necessary to bear in mind that the ventral 
view should be at right angles to the longitudinal axis, 
which axis is defined as the line running through the ap- 
ical horn and bisecting the hypotheca midway between 
the bases of the antapical horns. It must be remembered 
that when a specimen comes to rest at the bottom of a 
drop of mounting fluid it does not present this view. 
When a specimen of Peridinium depressum comes to 
rest with ventral side uppermost, it presents an antero- 
ventral aspect, resting on the dorsal side of the girdle 
and on the two antapical horns. This position should 
not be used as the standard in measuring, since consid- 
erable variation in the optical projection of the body is 
caused by slight differences in the length or divergence 
of the antapical horns on which the organism rests. It 
is necessary to mount in glycerin jelly or similar me- 
dium in order to orient the specimen in the proper man- 
ner and arrange it in a proper position. 

As defined in this work, the ventral view is the one 
in which the sulcus lies midway between the lateral 
sides of the body and in which the dorsal part of the gir- 
dle can be superimposed on the anterior end of the sul- 
cus when the microscope is focused downward. 

Because of the very great differences in the shapes 
of the various genera of the Peridiniales, it is not always 
possible or desirable to make the same measurements 



on all forms. There are particular dimensions which 
are significant in each genus. A description of these 
measurements and the method of making them will be 
given in the introduction to each genus. 

The question of nomenclature always arises in the 
treatment of this group of organisms. The group has 
been studied by both botanists and zoologists, each using 
the nomenclature of his particular school. It seems 
futile to discuss the question whether the members of 
this group are plants or animals. They cannot be placed 
unreservedly in either the plant or the animal kingdom. 
We can only discuss their relative similarities to each 
of these kingdoms. Since one is forced to adopt either 
plant or animal nomenclature, it is only reasonable that 
the nomenclature should fit the views of the author. This 
author believes that the plant characteristicsof the peri- 
dinians outweigh the animal. Hence, botanical nomen- 
clature is used in this report. Many of the peridinians 
are photosynthetic and practically all show some signs 
of a cellulose-like substance in their body wall (All- 
mann, 1855; Klebs, 1883; Schutt, 1895; Mangin, 1907, 
1908). The discovery of two filamentous algae with 
Gymnodinium spores by Pascher (1914) supports the 
interpretation of these forms as plants, but the discov- 
ery of an amoeba with similar spores (Pascher, 1915) 
tends to outweigh this discovery. 



SURVEY OF THE ORDER PERIDINIALES 



General Statements 

The Peridineae, or Dinoflagellata, are subdivided 
into two main groups: the Adiniferae and the Diniferae, 
the former without, the latter with a girdle, i.e., a body- 
encircling transverse groove in which the transverse 
flagellum is lodged. Diniferae are divided into seven 
orders, one of which is the Peridiniales, to which the 
material of this thesis belongs. 

The Peridiniales may be characterized briefly by 
the following features: The body is surrounded byathe- 
ca, which is made up of definite polygonal plates (ex- 
cept in prevalvate stages of Glenodiniaceae) of unequal 
sizes and not arranged in a bilaterally symmetrical 
manner. These features, especially the last one, sepa- 
rate the Peridiniales from the Dinophysiales, which is 
the remaining large order with thecate and plated body, 
and in which the theca is divided longitudinally into right 
and left valves. 

The most recent synopsis of the Peridineae which 
includes the Peridiniales is that of Lindemann (1928) in 
Engler and Prantl's Pflanzenfamilien. Kofoid, who 
worked extensively on the Peridineae, never treated this 
order as a whole. Schiller's synopsis of the Dinoflagel- 
lata (1931 to 1933) still lacks the part on the Peridini- 
ales. 



Families 

Lindemann (1928) divided the order into fourteen 
families. Instead of giving abbreviated diagnoses of 
these, a condensation of Lindemann's key for distin- 
guishing these families is given below in order to offer 
a brief survey of the order. 



Key to the Families of the Peridiniales 
(Lindemann, 1928, p. 79) 

A. Shell tough- skinned; composed of unequally sized, in- 
distinct, major polygons, not visible in young stages 
. . . . Glenodiniaceae 

A. Shell consists of more or less heavy armor composed 
of dissimilar polygonal plates which are evident in 
young stages B 

B. Girdle indistinctly developed as a narrow band . . 
Podolampaceae 

B. Cell with very distinct girdle C 

C. Cell in apical view quite or nearly circular; epitheca 
distinctly smaller than hypotheca, flat, lid-shaped. 
Either there are spinelike processes with a central 
axis which extend in different directions (each about 
as long as the body), or the antapical pole carries 2 to 
3 strong spines D 

C. Cell of other shapes; there are frequently processes 
or spines but these are never so long as the body nor 
with a central axis E 

D. Processes or spines only on the hypotheca .... 
Ceratocoryaceae 

D. Both epitheca and hypotheca carry long processes . 
Cladopyxiaceae 

E. Girdle equatorial or anterior; only one plate at the 
antapex, which terminates in a horn or spine . . . 

Oxytoxaceae 

E. Commonly at least two antapicals, or one antapical 
and one posterior intercalary; rarely one antapical, 
in which case there is no end spine or point . . F 

F. Cell strongly flattened anteroposteriorly; antapicals 
none or more than two G 

F. Cell otherwise shaped H 

G. Antapical plates absent (?); longitudinal axis oblique 



SURVEY OF THE ORDER PERIDINIALES 



G. At least three antapical plates present 

Pyrophacaceae 

H. On ventral side of epitheca where intercalary striae 
converge, there is a small but conspicuous field 
with a porelike point Heterodiniaceae 

H. Epitheca on the ventral side without such porelike 
point , I 

I. Cell with two to four characteristic horns; one 

apical, one to three antapical . . . Ceratiaceae 
I. Cell not so shaped J 

J. Theca so strongly reticulated on the surface that the 
tabulation is not discernible . . Protoceratiaceae 
J. Tabulation clearly evident K 

K. Posterior intercalary present in addition to one ant- 
apical Gpnyaulacaceae 

K. Two antapicals present Peridiniaceae 

K. Three antapicals present, one dorsal, two ventral . 
Goniodomaceae 

K. Only one plate at the antapex; not drawn out . . L 

L. Shape spherical, without apex . . Dinosphaeraceae 
L. Cell flattened; apex present; comb near sulcus . . 
Diplopsalis 



Genera 

The genera of the Peridiniales are described prin- 
cipally on the basis of the number and arrangement of 
the thecal plates. For purposes of terminology these 
plates can be arranged more or less in rows running 
parallel to the girdle. In this report the terminology of 
Kofoid (1909) has been followed. On the epitheca, ante- 
rior to and touching the girdle, is a row of plates, the 
precingular series. Another group of plates, touching 
the apex, is designated the apical series. Between 
these two rows there may be interpolated plates called 
the anterior intercalates. The girdle itself is made up 
of a series of plates. On the hypotheca there is a row 
bordering the girdle called the postcingular series. 
Another series, touching the antapex, is called the ant- 
apical plates. Between these and the postcingular ser- 
ies there may be interpolated other plates which are 
designated the posterior intercalaries. In the plate for- 
mulas the names of these plates have been abbreviated 
in the present paper as follows: 

apical platelet - pi postcingular - po 

apical plate - ap posterior intercalary - p 

anterior intercalary - a antapical - ant 

precingular - pr sulcal - s 
girdle - g 

These abbreviations are clearer and more rapidly read 
than the prime signs used by Kofoid (1909). 

The following list of genera of the Peridiniales is 
compiled chiefly from Lindemann (1928). There is con- 
siderable uncertainty in regard to the limits of some 
genera. For example, the genus Diplopsalis includes 
five genera considered distinct by some authors. The 
plate formula is given as far as is known for each genus. 

Acanthogonyaulax (Kofoid) nobis. 3ap, 0a, 9pr, 6g, 7s, 

6po, lant. 
Amphidoma Stein, 1883. 6ap, 0a, 6pr, 6g, ?s, 6po, lp, lant. 
Blepharocysta Ehrbg., 1873. 2ap, l-2a, 6pr, ?g, ?s, 

3po, 3ant. 
Centrodinium Kofoid, 1907. 2ap? 0a, 6pr, ?g, ?s, 5po, 

lp, 4ant. 
CeratiumSchrank, 1793. 4ap, 0a, 5pr, 4g, ?s, 5oo, Op, 2ant. 
Ceratocorys Stein, 1883. 2ap, 2a, 5pr, 6g, 5-6s, 5-6po, 



Cladopyxis Stein, 1883. 4ap, 0a, 8pr, ?g, ?s, 6po, Op, 

2ant. 
Congruentidium Abe", 1927. 4ap, la, 5pr, ?g, ?s, 5po, 

lp, 2ant. 
Dinosphaera Kofoid and Mich., 1912. 3ap, la, 6pr, 6g, 

?s, 5po, Op, lant. 
Diplopsalis Bergh, 1882. 3-4ap, 0-2a, 6-7pr, ?g, ?s, 

5po, Op, l-2ant. 
Dolichodinium Kofoid and Adamson, 1933. 4ap, 0a, 6pr, 

6g?, ?s, 6po, Op, 3ant. 
Glenodinium Stein, 1883. Variable pattern. 
Glenodiniopsis Wolosz., 1916. 7ap?, 0a?, 8pr, ?g, ?s, 

7po, 2ant. 
GonyaulaxDiesing, 1886. Formula for genus uncertain. 
Goniodinium Pavillard, 1927c. 4ap, 0a, 6pr, 9g?, ?s, 

6po, 2a, 3ant. 
Goniodoma Stein, 1883. Sap, 0a, 7pr, 6g, 5s, 5po, Op, 3ant. 
Heterocapsa Stein, 1883. 4ap, 2a, 6pr, ?g, ?s, 5po, Op, 

2ant. 
Heterodinium Kofoid, 1906. 3ap, la, 6pr, 6 (7?) g, ?s, 

7po, Op, 3ant. 
Lissodinium Matzenauer, 1933. 3(2?)ap, 0a, 5pr, ?g, 

?s, 5po, 4ant. 
Murrayella Kofoid, 1907. 2-4ap, la, 6pr, ?g, ?s, 4po, 

Op, lant. 
Ostreopsis J. Schmidt, 1901. 3ap, 0a, 7-8pr, ?g, ?s, 

4po?, lant? 
Oxytoxum Stein, 1883. 5ap, 0a, 5pr, ?g, ?s, 5po, Op, lant. 
Pachydinium Pavillard, 1915. 3ap, 0a, 5pr, ?g, ?s, 5po, 

Op, 3ant. 
Peridiniella Kofoid and Mich., 1911. 4ap, 3a, 7pr, 6g, 

?s, 6po, lp, lant. 
Peridinium Ehrbg., 1840. 2-5ap, 0-8a, 6-7pr, 3-6g, 5- 

6s, 5-6po, Op, 2ant. 
Podolampas Stein, 1883. 2ap, la, 6pr, ?g, ?s, 3po, 4ant. 
Protoceratium Bergh, 1882. 2ap, 0a, 6?pr, 6?g, ?s, 

6po, Op, 3ant. 
Pyrodinium Plate, 1906. 3ap, 0a, 6-7pr, 8g, ?s, 5po, 

lp, lant. 
Pyrophacus Stein, 1883. 5-9ap, 2?a,9-13pr, ?g, ?s, 9-13 

po, 0-2p, 3-4ant. 
Spiraulax Kofoid, 1911. 4ap, la, 6pr, 6g, 6s, 6po, lp, 

lant. 



State of Knowledge of Morphology 

In the above list there are thirty genera covering 
more than five hundred species. Although the generic 
classification of these species is based primarily on the 
plate pattern, our knowledge of this feature is far from 
complete, as can be seen by a glance at the above list. 
Many generic diagnoses are based on the analysis of 
only one or a few species. In many cases the tabulation 
given by the authors is admittedly only approximate. 
Some of the recorded generic plate formulas are decid- 
edly incomplete; e.g., for five genera not even the major 
plates of the epitheca and hypotheca have been reported 
with certainty. Among those genera for which formulas 
of the major epithecal and hypothecal plates have been 
reported without reservation, seventeen have not had the 
number of girdle plates reported or this number is un- 
certain. In only three genera had the ventral area been 
investigated before the present work. 

Under these conditions it is a matter of course that 
all the generic diagnoses may be subjected to more or 
less radical alterations on the application of more crit- 
ical morphological analysis. Further, a more extensive 
study of the various species will undoubtedly result in 
revised concepts of genera as well as of species. 

Over 1200 papers have been written on the Peridin- 
eae. More than 900 of these contain systematic or flo- 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



ristic treatments of some group or groups of the Peri- 
dineae; the remaining 300 deal with cytological, ecolog- 
ical, and physiological problems. Of the systematic 
papers, less than 5 per cent present critical analytical 
treatments of the species from either the taxonomic or 
the morphologic viewpoint. 

Forms Treated in this Report 

Of the fourteen families in the order Peridiniales, 
this report deals with representatives of five. A mono- 
graphic treatment has been given of the monogeneric 
family Ceratocoryaceae. This was due to the fact that 
ample material was available for making a complete 
skeletal analysis of every known species. Whereas in 
Ceratocoryaceae species are not difficult to define, in 
the family Peridiniaceae the species seem to be in an 
unstable condition; extreme variability frequently 
makes a delimitation of species a difficult task, indeed. 
One genus in this family was selected for study, viz., 
Peridinium . Of its two hundred or more species, those 
related to Peridinium depressum Bailey were selected 
for intensive studies of the variation in body shape and 
plate pattern. Representatives from other parts of this 
large genus were also analyzed, viz., P. crassipes Ko- 
foid, P. truncatum n.sp., and P. pallidum Ostenfeld. In 
an attempt to probe further into the interfamily rela- 
tionships, work was also done on three other families: 
Ceratiaceae, Goniodomaceae, and Gonyaulacaceae. One 
species from each of the first two was investigated, viz., 
Ceratium p avillardii Jorgensen and Goniodoma polyedri - 
cum Pouchet; and from the family Gonyaulacaceae four 
species were analyzed: Gonyaulax pacifica Kofoid, Gon- 
yaulax fusiformis n.sp., Acanthogonyaulax spinifera 
(Murray and Whitting) Graham, and Spiraulax kofoidii 
new name. 

Of the twenty-nine forms treated in this paper, 
there are six new species, three new varieties, and six 



new forms. Two old specific names have been replaced. 

Following is a complete list of the forms included 
in this report: 

Family Goniodomaceae 
Goniodoma polyedricum Pouchet 

Family Ceratocoryaceae 
Ceratocorys horrida Stein 
C. armata (Schiitt) Kofoid 
C. reticulata n.sp. 
C. aultii n. sp. 
C. bipes (Cleve) Kofoid 
C. skogsbergii n. sp. 
C. gouretii Paulsen 

Family Gonyaulacaceae 
Gonyaulax pacifica Kofoid 
G. fusiformis n.sp. 
Acanthogonyaulax spinifera (Murray and Whitting) 

Graham 
Spiraulax kofoidii new name 

Family Peridiniaceae 
Peridinium depressum Bailey 
P. depressum var. parallelum Broch 
P. depressum var. rectius n. var. 
P. depressum var. convexius n. var. 
P. depressum f. bisintercalares n.f. 
P. depressum f. multitabulatum n.f. 
P. claudicanoides n.sp. 
P. oceanicum Vanhoffen 
P. oceanicum var. tenellum n.var. 
P. oceanicum f. spiniferum n.f. 
P. oceanicum f. bisintercalares. n.f. 
P. oceanicum f. tricornutum n.f. 
P. crassipes Kofoid 
P. truncatum n.sp. 
P. truncatum f. acutum n.f. 
P. pallidum Ostenfeld 

Family Ceratiaceae 
Ceratium pavillardii Jorgensen 



RELATIONSHIPS AMONG THE GENERA 



General Considerations 

Our ideas of the relationships of the genera must at 
present be based on the degree of similarity in the skel- 
etal structures, since the cytology of the order is alto- 
gether too little known to be used for this purpose. For- 
tunately, the skeletons of these forms are complex and 
hence present a multitude of morphological characters 
useful in taxonomic studies. These characters have not 
been the basis for any satisfactory discussion of inter- 
generic relationships; indeed, so far no one has ventured 
into such a discussion. Ideas concerning these relation- 
ships have been expressed only by the grouping of the 
genera into families, without any discussion of the justi- 
fication for doing so (see, however, Lebour, 1922, on the 
origin of Peridinium ). 

The absence of such evolutionary studies is proba- 
bly due to the apparent lack of order in the great varie- 
ty of plate patterns which are presented by the various 
genera. It is extremely difficult to select, from this 
kaleidoscopic array of patterns, characters which are of 
fundamental generic or family importance. As stressed 



above, however, the incompleteness and undoubted inac- 
curacies in our knowledge of the skeletal features have 
greatly aggravated this situation. Doubtless the situation 
in nature is not so chaotic as present knowledge indicates. 

The skeletal features which are the most fundamen- 
tal from the standpoint of taxonomy are the number and 
arrangement of the thecal plates. The body shape, the 
lists and spines, and other such characters are of sec- 
ondary importance. 

In regard to the number of plates, there are variouf 
ways in which evolution may have taken place. For in- 
stance, primitive forms may have had relatively few 
plates and evolution may have progressed by the split- 
ting of plates or by the insertion of newly formed plates; 
or the primitive forms may have had a large number of 
plates and evolution may have proceeded by the fusion 
and loss of plates; or the processes of increase and de- 
crease may have taken place simultaneously in different 
parts of the body. 

Whatever has been the progress of evolution, it has 
not been uniform or parallel in all parts of the theca. 
Today there are some genera witn the same number of 



RELATIONSHIPS AMONG THE GENERA 



plates in the hypotheca as in the epitheca (Heterodini- 
um), some with more plates in the hypotheca ( Centro - 
dinium), and the majority have more in the epitheca 
than in the hypotheca. This is an expression of the well- 
known principle of the independent evolution of particu- 
lar organs or organ systems which is so amply illus- 
trated throughout the Metazoa. 

In regard to the arrangement of plates it is even 
more difficult to attempt a reconstruction of evolution- 
ary trends than in the case of the number of plates. We 
do not know of any forms which represent definite tran- 
sitional stages between the unarmored Dinoflagellata 
and the Peridiniales. Thus, we have no reasonably cer- 
tain information as to which are the most primitive pat- 
terns. As a consequence, we find ourselves forced to 
undertake a search for features which are more or less 
universal, and to start from the assumption that such 
characters represent the primitive condition. 

The peridinian skeleton is divided naturally into 
four parts and, for purposes of evolutionary discussions, 
it is advisable to consider these separately. They are: 
the epitheca, the hypotheca, the girdle, and the ventral 
area. 

Because of the unreliability of many of the pub- 
lished generic diagnoses, the present discussion of re- 
lationships is based entirely on the forms treated in this 
report. The skeletal features of these are known with 
certainty. Since the ventral area has been the main tar- 
get in the present work and, since the comparison of the 
ventral areas has been the most fruitful in showing in- 
tergeneric relationships, it will be taken up first. 

Ventral Area 

The ventral area was almost unknown in the Peri- 
diniales when this investigation was started. Since then, 
however, Abe (1936) has begun a reclassification of the 
genus Peridinium on the basis of the structure of this 
region, and Tai and Skogsberg (1934) have demonstrated 
the importance of this feature in the Dinophysiales. 

A study of this area in various genera of the Peri- 
diniales has shown that there is a rather small and fair- 
ly constant number of plates, and that the shape and ar- 
rangement of these plates differ fundamentally in the 
different genera. 

General shape. There has been an extensive evolu- 
tion of the general contours of the ventral area in the 
Peridiniales. The area is seen in its simplest form in 
Goniodoma , where it is comparatively flat and lacks in- 
tricate structures. Furthermore, in this genus there is 
no distinct delimitation of the sulcus proper. In Cerati- 
um the ventral area is specialized, being broad and rel- 
atively large, with extremely hyaline plates and with a 
small sulcus on the left side. In the other genera inves- 
tigated, there is a deep sulcal groove, in many cases so 
deep and narrow that no indication of the tabulation can 
be ascertained without dissection. In Spiraulax, Gon - 
yaulax fusiformis , and Acanthogonyaulax the posterior 
part of the ventral area flares out into more or less ex- 
panded areas which cannot be considered part of the sul- 
cus proper. In Peridinium this does not occur and the 
sulcus proper is usually limited. In this case the sulcus 
usually lies to the left side of the ventral area, although 
there is considerable variation in this respect within the 
genus. In P. truncatum , for example, the right sulcal 
plate is on a level with the major body plates, as is also 
the left limb of the posterior plate, and the left sulcal 



plate is turned in so that it forms the side wall of a 
deeply embedded groove. 

In most of the forms of the Peridiniales represent- 
ed in this report the two sides of the body are about 
equal in size, and as a consequence, the ventral area 
appears in or near the mid-ventral line when the organ- 
ism presents the ventral view. In Gonyaulax pacifica , 
on the other hand, a differential growth has taken place 
by which the left side has grown decidedly larger than 
the right. A consequence of this is that when the organ- 
ism presents the ventral aspect, the ventral area lies 
decidedly to the right and the axis of the sulcus has been 
so rotated that only the plates of the right side are visi- 
ble. 

Plate pattern. The ventral area in the forms investi- 
gated is composed of from five to seven external plates. 
(Fig. 1.) As regards homologues, however, there are 
eight plates, as is shown by the fact that in Acanthogon - 
yaulax , which has seven plates, there is a left acces- 
sory but no posterior accessory; and in Gonyaulax pa- 
cifica, which also has seven plates, there is a posterior 
accessory but no left accessory. 

Thus, the generalized composite picture of the ven- 
tral area has eight external plates. These are: an ante- 
rior, a posterior, a left and a right, with accessories to 
the left, right, and posterior, plus an intercalary in the 
right posterior region. All border on the flagellar pore 
except the posterior sulcal ( Goniodoma excepted) and 
the intercalary sulcal. In addition to these external 
plates, in Peridinium there is an internal plate lying 
along the right side of the pore. 

The anterior sulcal plate (as, fig. 1) forms the ante- 
rior edge of the pore in all genera except in Acantho - 
gonyaulax , where it has migrated anteriorly. The ante- 
rior plate in all cases lies against the proximal end of 
the girdle and in some genera it forms a distinct part of 
the girdle, as, for instance, in Goniodoma . Frequently 
this plate has a considerable extension into the epitheca, 
viz., in Goniodoma , Gonyaulax , and Spiraulax . In Peri - 
dinium the anterior plate bears part of the anterior in- 
ternal process. It can be concluded that the anterior 
sulcal plate is an important plate in the thecal complex 
of the peridinian skeleton. It is a conservative plate, 
occupying a key position at the head of the flagellar pore, 
at the proximal end of the girdle, and in the epithecal 
pattern. Only in Acanthogonyaulax is it removed from 
its position at the head of the pore, but even in this ge- 
nus it lies at the proximal end of the girdle. Its shape 
varies considerably from genus to genus, but none of the 
differences are radical. It may be squarish to linear 
with various numbers of sides or irregularities. Fre- 
quently the anterior cingular list is extended across it, 
as in Goniodoma and Gonyaulax . 

The posterior sulcal plate (ps, fig. 1) is another im- 
portant element. It is conservative in being always 
present, but it has undergone a much greater diversifi- 
cation than the anterior sulcal plate. It is always re- 
moved from the flagellar pore except in Goniodoma . In 
most genera it flares out into a relatively wide expanse 
on the ventral aspect of the hypotheca. This expansion 
may be elliptical ( Gonyaulax and Spiraulax ) or winged 
(Acanthogonyaulax ) . In Ceratocorys it is rather obscure, 
being rectangular and not wider than the anterior part of 
the sulcus. It attains its greatest complexity in the ge- 
nus Peridinium , where it is very intricate and lies at 
the posterior end of a deep sulcal groove. In this genus 
it is more or less horseshoe-shaped with a narrow cen- 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



tral part, a wide right limb lying posterior to the right 
sulcal plate, and a narrow or wide limb on the left side 
running along the left side of the left sulcal plate. In 
some species (P. truncatum) it assumes a size equal to 
that of some of the major body plates. It bears some of 
the elements of the more complicated list systems of 
the Peridiniales. 

The left sulcal plate (Is, fig. 1) is present in all ge- 
nera. It has undergone little evolution of shape, but 
varies in position in the sulcal tabulation. It is always 
anterior to the posterior plate, however, and on the left 
side of the area, and it always borders the flagellar 
pore. It may form the entire left edge of the pore, as 
in Peridinium and Goniodoma ; it may form the posteri- 
or edge and part of the left edge of the pore, as in Gon - 
yaulax ; or it may form only the posterior edge of the 
pore as in Spiraulax and Ceratocorys ; or only part of 
the posterior edge, as in Acanthogonyaulax . 

In only one genus, Acanthogonyaulax , is there a left 
accessor y sulcal plate (la, fig. 1). This lies not contig- 
uous t» the left sulcal plate, but anterior to the flagel- 
lar pore on the left side of the sulcus. 

On the right side of the ventral area there may be 
from one to three plates between the anterior and the 
posterior; viz., one in most species of Peridinium , two 
in Goniodoma , Ceratocorys , and Peridinium pallidum , 
and three in Gonyaulax , Acanthogonyaulax , and Spirau - 
lax. When only one plate is present, it is the right sul - 
cal plate (rs, fig. 1). Anterior to this plate there may 
be a right accessor y sulcal plate (ra, fig. 1); posterior 
to it, an intercalar y sulcal plate (i, fig. 1). Either the 
right or the right accessory, or both, borders the pore, 
but the intercalary never does. Sometimes the right 
is not in contact with the pore, as in Goniodoma and 
some species of Ceratocorys . In such cases the right 
accessory and the anterior sulcal plates form the right 
edge of the pore. In addition to these seven plates there 
is frequently an eighth, the posterior accessor y sulcal 
plate (pa, fig. 1). This lies between the posterior edge 
of the pore and the posterior plate as in Peridinium , or 
it may be squeezed out of contact with this plate as in 
Gonyaulax pacifica. It occurs only in these two genera. 

Discussion . It is obvious that there is a great 
diversity in the tabulations of the ventral areas of the 
various genera in the Peridiniales. In spite of this 
diversity, however, a common basic plan is evident. 

After a careful comparison of the ventral areas of 
the various genera, a type of tabulation was devised 
which may represent an approximation of the ancestral 
condition (fig. 1A). This reconstructed ventral area is 
quite similar to that of Goniodoma with the major ex- 
ception that its posterior sulcal plate does not touch the 
flagellar pore. Since all genera except Goniodoma have 
this plate removed from the pore, Goniodoma must be 
considered aberrant in this respect. This primitive 
ventral area is thus composed of five plates: an anteri- 
or sulcal, a posterior sulcal, a right and a left sulcal, 
and a right accessory sulcal. These plates are approx- 
imately equal in size and all border the pore except the 
posterior sulcal. The sulcal ring is complete. 

If this reconstruction of the ancestral ventral area 
is used as a key, a comparison of this area in the vari- 
ous genera yields the following results: 

Goniodoma : This is, without doubt, the most prim- 
itive of the genera investigated, since its ventral area 



is the simplest of those studied, being different from the 
ancestral condition only in having the posterior plate 
touching the flagellar pore. Its ventral area is very 
simple in outline and contour; the flagellar pore is ful- 
ly exposed; there are no internal skeletal structures; 
and the sulcal lists are poorly developed. There are 
only five plates. These are subequal in size and show 
no complex contours. The sulcal ring is complete. 

Ceratocorys : The genus Ceratocorys is evidently 
closely related to Goniodoma. The sulcal plates, also 
five, are simple in structure, and apparently are homol- 
ogous with the five present in Goniodoma . There has 
been a narrowing of the sulcus, however, and a slight 
enlargement of the posterior sulcal plate. The sulcal 
ring has broken on the left side and the posterior sulcal 
plate has taken up a position posterior to the right sul- 
cal plate so that it alone forms the posterior end of the 
area. The last two characters are carried through the 
other genera except that the ring is not broken in Peri - 
dinium . Thus although Ceratocorys is closely related 
to Goniodoma , it represents a definite advance over that 
genus. 

Gonyaulax , Acanthogonyaulax . Spiraulax: These ge- 
nera show striking similarities. Their ventral areas 
are greatly elongated and sigmoid ih outline, with great- 
ly enlarged posterior sulcal plate. The number of plates 
has increased to six or seven. The sulcal ring is bro- 
ken. The sulcus proper is a narrow groove occupying 
only part of the ventral area. All the plates of the 
primitive area are present, and in addition, there is an 
intercalary lying on the right side between the right and 
the posterior sulcal plates. In addition to these, Gon - 
yaulax pacifica has a posterior accessory plate just 
posterior to the pore. In Acanthogonyaulax there is a 
left accessory sulcal plate just anterior to the pore, and 
the anterior sulcal plate is unique in being removed 
from the pore. 

Peridinium, Ceratium : These two remaining gene- 
ra are widely divergent from the previous genera and 
each of them is unique in regard to its sulcal structures 
In Peridinium the primitive number of external plates, 
i.e., five, has been retained, except in P. pallidum ; and 
the sulcal ring is unbroken. Each sulcal plate, however, 
is singularly modified, particularly the posterior, and 
internal sulcal structures have developed. Sulcal lists 
are prominent and the sulcus proper is deeply embed- 
ded in the left side of the area in such a way that it is 
not exposed to view. Ceratium is characterized by the 
development of a wide and large flat ventral area ex- 
tending over the ventral side of the body, and covered 
by hyaline plates. This type is to be found nowhere else 
in the Peridiniales. 

It can be concluded from the above studies that 
Goniodoma represents the most primitive genus inves- 
tigated; that Ceratocorys is closely related to it but is 
somewhat more advanced; that Gonyaulax , Acanthogon - 
yaulax , and Spiraulax are decidedly more advanced and 



in addition are closely related to each other; and that 
the genera Peridinium and Ceratium are highly special- 
ized and developed along divergent lines. 

Thus, the genera cannot be arranged in a single 
evolutionary series. Evolution has apparently prog- 
ressed in divergent directions within the order and these 
divergent directions are expressed by an apparently 
natural grouping of the genera. 



RELATIONSHIPS AMONG THE GENERA 



The Girdle 

The number of girdle plates has not been generally 
determined by previous workers, and has frequently 
been omitted from generic plate formulas. Therefore, 
this feature is known for only a limited number of ge- 
nera. This is the more deplorable since there are in- 
dications from the present investigations that the num- 
ber of girdle plates may be important from a taxonomic 
standpoint. 

All the genera treated in this report have six gir- 
dle plates except Peridinium and Ceratium, which have 
four. Six is also recorded for certain other genera not 
treated in this report. Other numbers have been ques- 
tionably reported (see p. 3), but these aberrant num- 
bers must be checked by careful dissection before they 
can be included in evolutionary discussions. The num- 
ber is thus apparently constant and it is probable that 
six is the primitive number. Any deviation from this 
number should, at least for the present, be interpreted 
as a divergent feature. 

In regard to the relationships among the genera 
treated here, the number of girdle plates fits into the 
scheme devised by a comparison of the ventral areas 
and, at the same time, indicates a greater unity in the 
order as a whole. The six girdle plates in Goniodoma , 
Ceratocorys , Gonyauiax , Acanthogonyaulax , and Spirau - 
lax bring these genera more closely together. The di- 
vergent number, four, in Peridinium and Ceratium cor- 
roborates the previous conclusion that these two genera 
have been separated from the ancestral form for a long 
period of time. 

The Hypotheca 

When considering the hypotheca, we have to deal not 
only with the number of plates, but also with the pattern 
which these plates assume. For intergeneric studies it 
is sufficient to limit the discussion of patterns to a con- 
sideration of the number of plates in the individual ser- 
ies, inasmuch as the relative positions of the plates and 
the course of the sutures are usually of specific value 
only. Thus, the expression of plate pattern is itself re- 
duced to numbers. 

Table 1. Comparison of number of plates in the four 
parts of the theca of the genera treated in 
this report 



Genera 



Epi- 
theca 



Hypo- 
theca 



Girdle 



Vent, 
area 



Total 



Goniodoma 11 

Ceratocorys 10 

Gonyauiax 12 

Acanthogonyaulax . . 13 

Spiraulax 12 

Peridinium 16 

Ceratium 10 



8 


6 


5 


30 


8 


6 


5 


29 


8 


6 


6-7 


33 


8 


6 


7 


34 


8 


6 


6 


32 


7 


4 


5-6 


32-33 


7 


4 


? 


21+ 



In regard to the total number of plates in the hypo- 
theca, the genera treated here are divided into two 
groups (see table 1). The first group has eight plates 
and includes all the genera except Peridinium and Cera - 
tium . The second group has seven plates and includes 
these two genera. There is a striking parallelism here 
with the number of girdle plates, which substantiates the 
assumptions based on the comparison of ventral areas 
alone that Peridinium and Ceratium are divergent from 
the other genera. 



In regard to tne tabulation of the hypotheca a simi- 
lar grouping is indicated, except that Goniodoma is sep- 
arated from related genera (see table 2). There are, 
thus, three groups: Goniodoma with hypothecal formu- 
la 5po, Op, 3ant; Ceratocorys, Gonyauiax , Acanthogon - 
yaulax , and Spiraulax with formula 6po, lp, lant; and 
Ceratium and Peridinium with formula 5po, Op, 2ant. 
This corroborates the conclusions derived from a 
study of the ventral areas, but emphasizes the fact 
brought forth by the position of the posterior sulcal 
plate that Goniodoma represents a short, independent 
side branch, even though close to Ceratocorys . The 
approximate similarity of the pattern of Goniodoma 
with that of Peridinium and Ceratium must be consid- 
ered a result of convergence, since the three equally 
sized antapicals of Goniodoma present a fundamentally 
different plan from that of Peridinium or Ceratium. 

Table 2. Comparison of plate formulas of genera 
treated in this report 



Genera 



Pi 



ap 



Pr g 



po 



ant 



Goniodoma 1 30 76 5 5 3 

Ceratocorys 1 22 56 5 6 1 1 

Gonyauiax 1 3 2 6 6 6-761 1 

Acanthogonyaulax .1 30967 61 1 

Spiraulax 1?4 1 6 6 6 6 1 1 

Peridinium 2 4 3 7 4 5-650 2 

Ceratium 1 40 54 ? 5 2 



The Epitheca 

In considering the epitheca we have to deal with 
both the number and the arrangement of the plates, as 
in the case of the hypotheca. The total number of plates 
in the genera investigated ranges from ten to sixteen, 
and it shows no correlation with the grouping of the ge- 
nera indicated by the other parts of the theca (see ta- 
bles 1 and 2). In the other genera of the Peridiniales, 
not included in this report, the number of epithecal 
plates is also extremely variable, as is shown by the 
above list of generic plate formulas (p. 3). When we 
turn to the arrangement of these plates we find that 
here, too, no generic grouping can be made which will 
parallel that made on the basis of the hypotheca, girdle, 
and ventral area. In fact, of the genera reported here, 
no two have the same epithecal formula (table 2). It is 
thus evident that the evolution of the epitheca has been 
in many directions and that it has been decidedly inde- 
pendent of the evolution of the other parts of the theca. 

Summary 

On the basis of the above comparisons of the vari- 
ous parts of the peridinian skeleton, it is thus possible 
to draw some conclusions regarding the relationships 
of the genera studied and to postulate certain aspects of 
the course of evolution in the group. When the term 
"relationships" is used here, it is clearly understood 
that the true relationship is not always indicated by 
morphology. Results obtained in the field of genetics 
have clearly demonstrated that the closest morphologi- 
cal similarities do not always represent the closest re- 
lationships. For the time being, however, we must 
build our genetic discussion of the peridinians on the 
assumption that morphological similarities express de- 
grees of relationship, unless evidence clearly demon- 
strates that the similarities are due to convergence. 



10 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



The comparison of the morphological features of 
the ventral areas of the forms in this report indicates 
that Goniodoma is the most primitive genus investigat- 
ed. This is shown by the simplicity of contours, size 
equality, and small number of plates, viz., five, and by 
the closed sulcal plate ring around the pore. At the 
same time, the fact that the posterior sulcal plate is in 
contact with the pore shows that Goniodoma does not 
lie on the main line of descent but that it represents a 
short, independent evolutionary branch near the base of 
the general evolutionary path. Closely related to Goni - 
odoma , but distinctly more advanced, and representing 
a short, special side branch, is Ceratocorvs , which has 
the same number of sulcal plates. In this genus, how- 
ever, the ventral area is narrowed, the sulcal ring is 
broken, and the posterior sulcal plate is somewhat en- 
larged. Still more advanced than Ceratocorys , and 
closely related to each other, are Gonyaulax , Acantho - 
gonyaula x, and Spiraulax, in which the ventral areas are 
elongated and sigmoid, the posterior plate is greatly 
expanded, and the number of plates has increased to six 
or seven. Highly specialized and widely separated from 
all the above genera and also from each other are Peri - 
dinium and Ceratium . The ventral area of Peridinium 
has a complex arrangement of intricate plates and lists, 
whereas in Ceratium this structure is a wide, flat ex- 



panse of hyaline plates. 

The comparison of the girdle plates corroborates 
the above conclusions, inasmuch as it separates the ge- 
nera Peridinium and Ceratium from the others. At the 
same time, it indicates that these two genera are mutu- 
ally closer than either of them is to the remaining genera. 

The comparison of the total number of hypothecal 
plates shows an exact parallelism with that of the gir- 
dle plates; there are seven in Peridinium and Ceratium 
and eight in the others, thus again bringing Peridinium 
and Ceratium together. 

The patterns of the hypothecal plates separate 
Goniodoma from Gonyaulax , Acanthogonyaulax , and 
Spiraulax , showing, as is stressed above, that Gonio - 
doma does not form a direct ancestral type. 

The comparison of the epithecal plates does not 
contribute to this picture, but rather indicates an inde- 
pendent structural differentiation. No two of the genera 
have the same epithecal formula. 

Thus we are able to build up a plan of evolution and 
relationships of the genera treated in this report, based 
primarily on the ventral area and nicely corroborated 
by the girdle and hypothecal tabulations (see fig. 2). As 
more accurate knowledge is gained of the other genera 
of the Peridiniales, it is hoped that these, too, will fit 
into this general scheme. 



FAMILY PERIDINIACEAE 



11 



SYSTEMATIC DESCRIPTION 



As indicated on page 4 , the following families are 
included in this paper: Peridiniaceae, Ceratocoryaceae, 
Gonyaulacaceae, Goniodomaceae, Ceratiaceae. The ar- 
rangement of the families does not indicate relation- 
ships, but rather expresses the degree to which the fam- 
ilies have been studied; the first ones the most inten- 
sively. 

Family PERIDINIACEAE 

Diagnosis . "Shape of the cell variable, spherical 
to longish; small horns often on the hypotheca. Apex 
present or absent. Girdle circular or somewhat spi- 
raled; there are right and left spirals. Theca in 'youth' 
quite thin, later usually developed into stronger theca 
which falls apart into dissimilarly shaped polygonal 
plates. Tabulation very different, variable, malforma- 
tions even common. It is scarcely possible to set up 
for Peridinium and its relatives, general valid plate 
patterns; mostly there are 6-7 precingular plates, 5-6 
postcingular, and 2 antapical plates which only in Di- 
plopsalis may be coalesced. The tabulation of the epi- 
theca is more variable than the hypotheca. Surface of 
the theca with areolae, papillae, spines, lists, or pores; 
seldom smooth. Plasma of marine forms sometimes 
colored. Stigmas in freshwater forms rare and little 
considered, often pale. In marine forms pusules. 
Chromatophores often in large numbers. Plasma inclu- 
sions, starch, fatty substances, pyrenoids, rods (rhab- 
dosomes). Nucleus roundish to longish. Colony forma- 
tion in one case. Formation of cysts after casting of 
theca. Different kinds of reproduction. Length 18 mi- 
crons to 300 microns. Fresh-, brackishwater, and ma- 
rine." (Lindemann, 1928, p. 88.) 

Three genera are established at present. They can 
be differentiated in the following manner according to 
Lindemann (1928, p. 88): 

A. Only one of the antapical plates drawn out into a 
short, hollow horn or spinelike point; shape + spin- 
dle-shape Heterocapsa 

B. Cell otherwise shaped 

a. Shape at both poles more or less ellipsoidally 
compressed; at the left margin of the longitudinal 
furrow (on the hypotheca) is a conspicuous list 
which can reach over to the antapex; antapical 
plates two, rarely one Diplopsalis 

b. Otherwise shaped, two antapical plates 

Peridinium 

Remarks . The above description and key clearly in- 
dicate the insufficiency of our present knowledge. This 
allows us to make neither a clear-cut definition of the 
family Peridiniaceae as contrasted with the remaining 
families, nor to establish generic diagnoses and descrip- 
tions which will fit into the family description and at the 
same time be exclusive and distinct. It should be empha- 
sized that Lindemann (1928) was not at fault. His at- 
tempt at classifying the Peridineae was remarkably suc- 
cessful, considering the meager data at his disposal. 
The only genus of the family treated in this report is 
Peridinium. 



Genus PERIDINIUM Ehrenberg 
Diagnosis 
See Lindemann, 1928, p. 89. 
Description 

Remarks . Because of our present hazy conception 
of this genus, a redescription is necessary. The follow- 
ing description is based solely on the representatives in 
which the skeletal morphology has been worked out in 
detail. It is intended to be but tentative and thus to be 
filled in and rounded out as more material accumulates. 
It must be stressed, however, that amendment should be 
made only on the basis of material obtained by the com- 
plete dissection of specimens and of material subjected 
to a statistical analysis of form variation. 

Dimensions . Among the forms in this report the 
total length (1_) varied from 44 microns in P. pallidum 
to 275 microns in P. truncatum; the diameter (d) from 
35 microns in P. pallidum to 200 microns in P. trunca- 
tum. Many other forms ascribed to this genus are 



smaller; e, 
Shape . 
P 



g., P. faer5ense is 16 microns in diameter. 



All the forms treated in this report, except 
pallidum, possess three well-developed horns, al- 
though many other species ascribed to the genus are 
hornless and some even spineless, and, in extreme 
cases, completely spherical. Whether all these species 
should be regarded as generically identical cannot be 
decided at this time. The body is usually longer than 
wide, but may be spherical, though rarely wider than 
long. All the forms here treated are much longer than 
wide, owing primarily to the long horns, the J/d ratio 
being as high as 1.5 in P. truncatum . The h/d ratio, 
which expresses the length of the body exclusive of the 
antapical horns (h) relative to the diameter, varies 
from 0.53 in P. claudicanoides to 1.76 in P. depressum 
var. tenellu m. The angle which expresses the amount 
of anteroposterior compression of the body oc varies 
from 78° in P. depressum to 139° in P. depressum var. 
convexius . 

Girdle . The girdle is more or less equatorial, 
sometimes encircling the body in one plane, but usually 
forming either a descending or an ascending spiral. Al- 
though it is usually displaced, there is never any over- 
hang. It seldom encircles the body at right angles to 
the longitudinal axis, but is deflected from this position; 
in the forms treated herein, this deflection is from 10° 
to 15°. The girdle may or may not be excavated. 

Sulcus . The sulcus is a groove on the ventral side 
of the body extending from the ends of the girdle, or 
from somewhat anterior to them, to the antapex of the 
body. In it lies the flagellar pore. The pore is usually 
oval in shape and the theca of the sulcus is so con- 
structed that the pore opens laterally instead of directly 
ventrally. The plate complex of the sulcus may spread 
out to some extent, forming a wide ventral area with the 
sulcus proper located within it. 

Plate pattern . If the broad generic concept of 
Lindemann (1928) is accepted, there are a great number 
of plate patterns represented in the members of Peri - 
dinium . This is particularly true of the epitheca. The 



12 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



only constancy in the entire pattern in Peridinium s. 1. 
is the absence of posterior intercalaries and the pres- 
ence of two antapicals. For abbreviations of the names 
of the plates, see above, p. 3. 

In the forms treated in this report the pattern of the 
major body plates is as follows: 

4ap (5 in P. depressum f. multitabulatum n.f.); 

3a (2 in P. depressum f. bisintercalares and P. oceani- 

cum f. bisintercalares n.f.); 
7pr (8 in P. depressum f. multitabulatum n.f.); 
4g; 5po; Op; 2ant. 

The four girdle plates are of unequal length. The 
third is the longest, comprising all the dorsal and later- 
al sides of the girdle and, in P. p allidum , most of the 
ventral side also. The other three lie ventrally and are 
comparatively small. The girdle plates may be very 
significant in the classification of the genus, the number 
being of generic value, and the pattern subgeneric. The 
determination of the girdle plates has too often been 
neglected in analysis of the thecal pattern, in spite of 
the fact that their dissection is not difficult. 

The epitheca of Peridinium is in an unstable condi- 
tion, as will be pointed out later. In all species dissect- 
ed, however, there was found an apical ring platelet and 
a ventral apical platelet. No variation was found in the 
number of girdle plates nor in the hypotheca except in 
P. oceanicum f. tricornutum n.f. 

Probably the most important region of the theca to 
be investigated at the present time is the ventral area 
or sulcal region. This is a very complex area made up 
of several plates. The necessity of dissection in deter- 
mining these structures has retarded our knowledge of 
them. Kofoid (1909) reported on this region in P. steinii, 
but it is not certain that complete dissections were made 
and his analysis must be verified before being accepted 
into the general concept of the ventral area of Peridini - 
um . Faure-Fremiet and Puigeandeau (1922) indicated 
plates in the ventral area of several species of Peridini- 
um including P. oblongum and P. crassipes . They show 
seven plates. These must have been drawn from the 
authors' imagination, as they bear no relation whatever 
to the actual tabulation of these species. The same may 
be said for the sutures shown encircling the antapical 
horns (fig. 9). The only detailed analysis of this area in 
the genus so far published which is at all acceptable, is 
that of Abe (1936) for Peridinium ovatum and related 
forms. These analyses can be incorporated into the 
general scheme developed from our own several analy- 
ses in widely separate representatives of the genus. 

Certain features of the plate pattern of the ventral 
area in the genus Peridinium are conservative; others 
vary from species to species. The number of plates is 
not constant in the genus, but varies from five to six; 
different plates may be wanting. The conservative ele- 
ments are represented by four plates: an anterior , a 
posterior , a right , and a left sulcal plate. These plates 
are conservative in that they are always present and 
always have the same relation to each other and to the 
flagellar pore. They do vary considerably in shape, 
however, in the different species. The anterior sulcal 
plate occupies the area between the ends of the girdle 
and joins the posterior end of the first apical; it extends 
to the anterior edge of the flagellar pore. The posterior 
plate is a very complex structure, the most complex 
plate so far found in the peridinian skeleton. Its shape 
is roughly that of a U in which one limb has been rotat- 



ed so that its axis lies at right angles to that of the 
other. The curve of the U is narrow, and the limbs are 
expanded into wide areas. The details of the shape will 
be described under each species. The right plate is the 
largest of the ventral area and forms the right edge of 
the flagellar pore. It extends from the anterior to the 
posterior sulcal plate. It bears a prominent list on its 
left margin, the right accessory sulcal list, which over- 
lies the pore and may bear processes which project into 
the protoplast. This plate is a prominent element of the 
ventral area in undissected specimens. The left sulcal 
plate is deeply set in the sulcus and is not clearly seen 
without proper cleaning or dissecting of the specimen. 
It is, however, fairly large and forms the left side of 
the ventral area and the left edge of the flagellar pore. 
It is one of the most constant elements of the area and 
varies but little from species to species. In addition to 
these four principal plates, the ventral area may have 
three other plates, although all of these never occur 
simultaneously. They are: the right accessor y sulcal 
plate , the posterior accessor y sulcal plate , and the right 
internal sulcal plate . The right accessor y sulcal plate 
lies against the distal end of the girdle. It was found 
only in P. pallidum and it represents simply the anteri- 
or end of the left sulcal plate in other forms. The pos- 
terior accessor y sulcal plate lies between the right and 
the left and the posterior sulcal plates, thus forming 
part of the posterior margin of the pore. It occurs in 
all the species, and is comparatively large in P. trunca - 
tum (24 microns long) and extremely minute (about 2 
microns long) in the other species investigated. The 
right internal sulcal p late is a part of the complex inter- 
nal skeleton on the inner side of the right sulcal plate. 
It was found only in P. crassipes and P. depressum. 

The apex of the theca is quite complex, with the 
same general structure throughout all the species inves- 
tigated. Only three of the four apical plates actually ex- 
tend to the apex; the first is subtended by a narrow 
plate, the ventral apical p latelet. The apical ends of this 
and of the second to fourth apical plates are joined to- 
gether around the apical pore platelet , which is a ring 
embedded in the apex. 

Structure of thecal wall . Little is known of the de- 
tailed structure of the thecal wall. It is quite thick in 
all the species investigated. Its exact thickness is dif- 
ficult to determine, but it is probably 1 to 2 microns in 
the thinner parts and considerably more in the thicker 
parts. The surface is variously marked with reticula- 
tions or tubercles. All the species are porulate at least 
in the larger plates; sometimes some of the sulcal 
plates are entirely smooth. 

In the species investigated, all plates are fastened 
together by rabbet joints, as has been shown for other 
species by Peters (1928). This joint is constructed as 
follows: Along each suture of the theca there is attached 
to one of the two adjoining plates a strengthening mem- 
brane which underlaps the adjacent plate, forming a 
rabbet joint (fig. 3A). Thus there are an external and 
and internal suture separated from each other by the 
width of the membrane. These membranes are an inte- 
gral part of the plate to which they are attached and can- 
not be detached from it. They occur whether or not there 
is an intercalary zone. When such a zone is present, 
the external suture divides it approximately in the mid- 
dle, so that when the two plates are separated, half of 
the zone remains attached to the plate without the mem- 
brane and half to the plate with the membrane. Since 



FAMILY PERIDINIACEAE 



13 



the rabbeting membrane is apparently of the same 
width in specimens with and without intercalary zones, 
there must be some intercalated material at the inter- 
nal suture as well as at the external suture, as shown in 
figure 3B. If this be true, then there is an internal as 
well as an external intercalary zone with the internal 
suture bisecting it approximately in the middle. 

Lists . Although never developed to the extreme de- 
gree that they are in some members of the Dinophysi- 
ales, nevertheless, lists form a prominent part of the 
thecal morphology of Peridinium . The girdle lists are 
always well developed and the posterior girdle list is 
usually confluent with the sulcal lists. The ventral area 
has a complex system of lists. This area is usually en- 
closed by the right, posterior, and left sulcal lists, and 
internal to these there may be right, posterior, and left 
accessory sulcal lists. These will be described under 
each species. The apex is another region of complexi- 
ty as regards lists. It is encircled by a list made up of 
parts of three lists attached to the apical plates. These 
lists always extend down the ventral side of the body as 
far as the posterior end of the ventral apical platelet, 
but may extend down the ventral and lateral sides of the 
body part way or entirely to the girdle. These will be 
described in detail in the individual species descriptions. 
No prominent body lists are developed except along 
plate sutures. The transverse ridges across the girdle 
sometimes, however, take on the character of lists. 

Spines . Antapical spines are developed in some 
species (e.g. P. pallidum ) in place of antapical horns. 
No other spines occur. The "apical spines" and the 
"antapical spines," internal to the antapical horns 
sometimes indicated in published figures, are not spines 
at all but are optical effects produced by the curvature 
of lists. 

Historical Review 

Peridinium is the largest and probably the most 
widespread genus of the Peridineae. More than two hun- 
dred species have been described. Thirty-eight of these 
are fresh-water forms, the rest are marine. 

There are many morphological characters in addi- 
tion to the general body shape which can be used in de- 
fining the species. Unfortunately, however, these char- 
acters are variable. Because of the pronounced intra- 
and interspecific plasticity, the genus is the most diffi- 
cult in the Peridineae from the standpoint of the system- 
atise So far no one has had the courage to attempt a 
generic monograph, a fact which is fortunate since it 
would, necessarily, have been only an abortive attempt 
because of our ignorance in regard to the pertinent data. 
Such a treatment can be made only after we have ac- 
quired a thorough knowledge of the thecal morphology of 
each of the species. 

Furthermore, the generic concept is one of the 
vaguest in the Peridineae. It has been very changeable, 
being sometimes narrow, sometimes broad. For exam- 
ple, Lindemann's concept (1928) of the genus included 
four described genera besides Peridinium of previous 
authors. Generally speaking, the confusion in the genus 
progressed as the number of described forms increased. 
It is fair to predict, however, that, when all the mem- 
bers of this vast genus have been thoroughly analyzed, a 
satisfactory classification will be evolved in spite of the 
variation in some features which now baffle our attempts . 

The first grouping of the species of Peridinium was 



made by Gran (1902). He divided the genus into two 
subgenera: Protoperidinium and Euperidinium . Proto - 
peridinium was adopted by Gran fromBergh (1881), who 
applied this name to a group of species to which he as- 
signed generic value. The name Euperidinium , on the 
other hand, was introduced by Gran. Protoperidinium , 
according to Gran, is characterized by solid antapical 
spines and by a right-handed girdle, i.e., on the ventral 
side of the body the right (distal) end of the girdle is 
located anteriorly to the left (proximal) end. Euperi - 
dinium is characterized by hollow antapical horns and 
by a left-handed girdle, i.e., the left end of the girdle is 
displaced anteriorly. Gran listed the following species: 
Protoperidinium : P. pellucidum Bergh s.l., P. ovatum 
Pouchet, P. decipiens Jorg., P. steinii Jorg., P. globulus 
Stein, Euperidinium : P. conicus Gran, P. pentagonum 
Gran, P. divergens Ehr. s. s., P. depressum Bail. s.L 

This classification was satisfactory for the few 
species that were known at that time and was accepted 
by many authors. Later investigators, however, re- 
vealed forms which could not be classified on the basis 
of these criteria. For instance, forms were found with 
a left-handed girdle, but with solid antapical horns. 
Furthermore, forms with no definite displacement of 
the girdle in either direction were discovered. 

Paulsen (1908) used Gran's classification in the 
treatment of thirty-nine species of Peridinium although 
he was compelled to acknowledge exceptions to the sys- 
tem. Thus, in Protoperidinium he included two species, 
P. findlandicum Paulsen and P. granii Ostenfeld, which 
have hollow horns. Those forms in which there is no 
displacement of the girdle he placed in Euperidinium . 
The description of this subgenus was further qualified 
by the statement that there are usually hollow horns. 
Paulsen was the first to show discrepancies in theGran- 
ian classification. 

Broch (1910) noted the inadequacy of the classifica- 
tion based on the displacement of the girdle and the struc- 
ture of the antapical horns. He also pointed out that the 
arrangement of the plates of the theca afforded a ready 
diagnostic means. Although he grouped his ten species 
from Val di Bora under the subgenera Protoperidinium 
and Euperidinium , he carefully described under each 
species the conformation of the first apical plate and 
figured the plate pattern for each form. 

Finally, Jorgensen (1913) made a comprehensive 
reclassification of the genus on the basis of the plate 
pattern, using the number of plates that border the first 
apical as a primary character in the formation of sub- 
genera and the pattern of the dorsal plates as the cri- 
terion for the division of the subgenera into sections. 

Jorgensen divided the genus Peridinium into two 
subgenera, Orthoperidinium and Metaperidinium , and 
discarded the subgeneric names used by Gran. Ortho - 
peridinium is characterized by a first apical which 
touches only four of the major plates of the epitheca; the 
second apical and first precingular are on the left side, 
the fourth apical and seventh precingular on the right 
side (fig. 4A). Metaperidinium is characterized by a 
first apical plate which borders five or six of the prin- 
cipal plates of the epitheca; the second apical and the 
first and second precingulars are on the left side, the 
fourth apical and the seventh, or the sixth and seventh, 
precingular on the right side (fig. 4B, C). 

Orthoperidinium was divided into three sections, 
principally on the basis of the dorsal epithecal plates, 
as follows: 



14 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Tabulata, in which the second anterior intercalary 
borders the third and fourth or the fourth and fifth pre- 
cingular plates (fig. 5C). 

Conica , in which the second anterior intercalary 
touches the third, fourth, and fifth precingulars (fig. 5B). 

Oceanica , in which the second intercalary touches 
only the fourth precingular (fig. 5A). 

Metaperidinium was divided into four sections, as 
follows: 

Pvriformia , in which the second anterior intercalary 
plate touches two precingular plates, as in section Ta - 
bulata of Orthoperidinium (fig. 5C). 

Paraperidinium , in which the second intercalary bor- 
ders the third, fourth, and fifth precingulars (fig. 5B); 
the first apical plate is bounded by six of the major 
plates of the epitheca (fig. 4C): the second apical and 
first and second precingulars on the left side, the fourth 
apical and sixth and seventh precingulars on the right 
side. Jorgensen did not give this group subgeneric rank 
because there was considerable variation in the length 
of the suture between the first apical and sixth precin- 
gular plates; the suture is sometimes quite short. 

Humilia , in which the second intercalary touches only 
the fourth precingular (fig. 5A); with solid antapical 
horns. 
Divergens , as Humilia but with hollow antapical horns. 

Jorgensen thus established not less than seven cat- 
egories for the grouping of the species of Peridinium . 
The number had thus become greater than when Gran 
devised his simple classification, and it demanded a 
more rigorous examination of the material. 

Although the thecal plates in Peridinium were 
known by Jorgensen to present several patterns, the 
number of plates in the theca was considered by him to 
be constant. He (1913) described the genus as having 
three anterior intercalary plates. Forms which had 
only two intercalates and which had been included in 
Peridinium by others he placed in a new genus, Archae- 
peridinium (fig. 6B). 

Jorgensen's comprehensive classification of the Pe- 
ridinium species on the basis of the plate pattern laid 
the foundation for a clearer understanding of the com- 
position of, and the relationships within, the genus than 
had ever before been possible. It promised to end the 
taxonomic difficulties which this genus presented. His 
classification was accepted by practically all later 
workers up to the present time and has been extremely 
helpful. 

As is shown in this paper, however, even this sys- 
tem is not adequate for the proper classification of the 
great number of variants which occur. 

Paulsen (1931) revised the system of Jorgensen 
(see also Peters, 1928, and Dangeard, 1927). He con- 
sidered the classification of Jorgensen unnatural, and 
proposed a system in which not only the plate pattern, , 
but a combination of plate pattern and other characters 
was used. He abolished the subgenera of Jorgensen but 
retained the sections with some revision. 

Paulsen (1931) referred to Jorgensen's Archaeperi - 
dinium as a subgenus of Peridinium , as had been done 
by Lebour (1925) and others. This subgenus is charac- 
terized by having only two anterior intercalary plates. 

The second subgenus, with three intercalary plates, 
Paulsen called Veroperidinium . This is equivalent to 
the subgenus Peridinium proper of Lebour. 



Paulsen divided the subgenus Archaeperidinium into 
two sections: 

Avellana , in which the two intercalaries are equal. 

Excentrica . in which the two intercalaries are very un- 
equal. 

The subgenus Veroperidinium he divided into eight 
sections, seven of which corresponded roughly to the 
sections of Jorgensen. The eighth section, Paradiver - 
gentia, was new. A summary of his sections of Vero - 
peridinium follows. In describing the relation of the 
dorsal plates he used the terms "quadra," "penta," and 
"hexa" to designate the number of sides on the second 
anterior intercalary, and "ortho," "meta, " and "para" 
to designate a four, five, or six-sided first apical. 

Pellucida : Para hexa, rarely para penta or quadra or 
meta hexa. Right-handed. Without antapical horns; has 
two, or more frequently three, antapical spines. This 
section corresponds to Paraperidinium of Jorgensen. 

Humilia : Meta quadra. Right-handed, without horns, 
but often with two antapical spines. 

P vriformia : Meta penta, rarely quadra or hexa. Right- 
handed, without antapical horns, but in general has two 
antapical spines. 

Tabulata : Ortho penta or hexa or quadra. Left-handed 
or with circular girdle. Cell round, without horns or 
spines, or with slight spines. 

Paradivergentia : Para quadra or hexa. Right-handed 
or with circular girdle; with two hollow antapical horns. 

Divergentia ( =Divergens Jorgensen): Meta quadra, 
rarely penta. Girdle circular or right-handed; with two 
hollow antapical horns. 

Oceanica : Ortho quadra, rarely penta or hexa (or even 
para). Left-handed. Girdle oblique relative to the lon- 
gitudinal axis of the body. Epitheca narrows into an ap- 
ical horn; two hollow antapical horns. 

Conica : Ortho hexa, more rarely penta or quadra. 
Girdle circular or left-handed. Body square or rhom- 
boid in ventral view, without apical horn but usually 
with two hollow antapical horns. 

Paulsen's classification is an improvement over 
Jorgensen's (1913), for it takes into consideration the 
occurrence of a greater number of combinations of char- 
acters. In so doing, however, Paulsen acknowledged the 
occurrence of a greater number of variations in the 
characters which have been used as fundamental taxo- 
nomic units. 

All the classifications devised so far have been 
based on a certain stability of the plate pattern within 
the species, particularly in the region of the first apical 
plate and the dorsal epithecal plates. Furthermore, all 
are based on the presence of three anterior intercalary 
plates in Peridinium proper. As is shown below, in the 
present investigations, forms in the section Oceanica 
have been found with only two intercalary plates. 

It should finally be noted that should a subgeneric 
classification be re-established for the sections, this 
must be done with due consideration to the international 
rules of nomenclature. When a new classification is 
proposed, there is no justification for the introduction 
of completely new terms. Old names must be retained, 
with only the termination changing if they are given al- 
tered rank (International Rules of Botanical Nomencla- 
ture, 1935, art. 51). These rules were completely disre- 
garded by Jorgensen and Paulsen. Thus Gran's subgenus 
Protoperidinium, for instance, has not been perpetuated. 



FAMILY PERIDINIACEAE 



15 



Methods of Study 

Selection of material . Since it would have been an 
insurmountable task to treat a really representative 
number of species of this large genus, a compromise 
plan of study had to be devised. For the sake of render- 
ing an initial contribution to the exact knowledge of the 
thecal morphology of Peridinium , representatives from 
each of the major groups of the genus were selected for 
detailed dissection, viz., P. depressum from Orthoperi- 
dinium , P. crassipes and P. truncatum from Metaperi - 
dinium, and P. pallidum from Paraperidinium . The re- 
sults of these investigations give some information a- 
bout both the generic unity and the interrelationships of 
the lower than generic groups. 

In addition to these detailed dissection studies, a 
statistical analysis was made of Peridinium depressum 
and of its relatives comprising the Formenkreis Peri - 
dinium depressum of Broch (1906). This work was un- 
dertaken in order to establish a method of attack on a 
very variable group. Thus, these studies have a three- 
fold purpose: first, to acquire a knowledge of skeletal 
morphology; second, to learn something of specific in- 
terrelationships and generic unity; third, to inquire into 
the nature of specific variability, a feature of exception- 
al significance in this group. 

Measurements . In determining the size and in com- 
puting ratios expressive of the shape of the Peridinium 
body, certain measurements were used. Measurements 
made with the specimen presenting the ventral face 
(p. 1) are indicated schematically by figure 7. Desig- 
nations of dimensions in that figure are as follows: a, 
length of right antapical horn, considering the base of 
the horn as a curved continuation of the lateral body 
contour running to the base of the right side of the sul- 
cus; b, thickness of the right antapical horn measured 
midway between its base and apex; d, diameter of the 
body at the girdle; h, distance between the end of the ap- 
ical horn and the base of the right side of the sulcus; J, 
total length, or distance between the ends of the apical 
and right antapical horns; a., the angle representing the 
degree of convexity of the lateral profile. The angle a 
is constructed with its vertex in the girdle at the right 
edge of the body, and with its sides intersecting the body 
walls at points at a distance from the vertex equal to 
one-fourth of d. 

Measurements made with the specimen presenting 
the apical view are indicated schematically by figure 8. 
Designations of dimensions in that figure are as follows: 
Z, dorsoventral diameter measured through the mid- 
body; r, in some species, e.g., P. truncatum , it is nec- 
essary to measure the prolongation of the ventrolateral 
limbs of the body in the equatorial region. The value r 
is obtained as follows: Construct a line passing through 
the apex (b) and the farthest point on the right limb (a). 
On this line erect a perpendicular at point c. The point 
c is determined by its distance from a which equals one- 
third g. The thickness of the limb, r, is measured along 
this perpendicular. 

Various features of the body shape can be expressed 
by the dimensional proportions. The best reference for 
most of these ratios is the diameter (d). It can be meas- 
ured in either the ventral or the apical view and is in it- 
self a good standard for the absolute size of the speci- 
men. 

The general body form can be expressed by the 



angle a. and the ratio of the length to the diameter of the 
body. In computing the latter ratio, h, was frequently 
used instead of, or in addition to, 1 because a slight 
displacement of the specimen sometimes caused more 
error in j_ than in h on account of the divergence of the 
right antapical horn in some forms. The distance h 
does not include the antapical horn, which has a tenden- 
cy to vary more than the apical horn, so that the value 
h/d gives a more accurate criterion of the length of the 
body than does the ratio j/d. 

In expressing the relative length of the antapical 
horns, it is usually necessary to measure only one of 
these structures, as the variation is usually proportion- 
al. In this work the length of the right horn was meas- 
ured, as it usually presents a truer value because of its 
lesser degree of inclination in the ventral view. The 
length relative to the diameter of the cell, a/d, was then 
computed. For the relative thickness of the antapical 
horns the ratio b/a, the thickness of the right antapical 
horn in relation to its length, was computed. 

Where the shape of the body in apical view was im- 
portant, the g/d ratio was computed. The thickness of 
the lateral limbs in apical view was found to be best ex- 
pressed by the ratio r/g. 

The width of the girdle was always measured and 
many smaller measurements referred to this. 



Peridinium depressum Bailey and related forms 

Introductor y remarks . Broch (1906) designated as 
the "Formenkreis Peridinium depressum Bailey" a 
group of highly variable and intergrading forms closely 
related to P. depressum Bailey. This species is an 
Orthoperidinium with a four-sided second anterior in- 
tercalary plate. The members of the group present one 
of the most difficult taxonomic problems of the Peridi- 
neae. They have been studied by several investigators, 
whose results have been at variance and decidedly con- 
fusing. Because of this fact, and since the Carnegie col- 
lection was rich in these forms, this group was subject- 
ed to an intensive analysis in order not only to solve the 
problems of this particular group, but also to formulate 
methods and concepts which might be applied to the ge- 
nus as a whole or to other groups of the Peridineae 
which present a series of variable and intergrading u- 
nits. 

Diagnosis . The group as conceived in this report 
includes all the species of Orthoperidinium in which the 
plane of the girdle is inclined to the longitudinal axis. 
All these species are confined to Jorgensen's section 
Oceanica . They are, indeed, the only forms now known 
in the entire genus with a strongly inclined girdle, ex- 
cept P. amplum Matzenauer. In the latter species, how- 
ever, the apical and antapical horns do not lie in the 
same plane, a feature characteristic of the "Formen- 
kreis." The species in this group are mostly large, u- 
sually with prominent horns, and the girdle is left-hand- 
ed. 

Extent of the group . The following forms have been 
described in the literature: 

P. depressum Bailey (1855) 

P. depressum f. brevisulcatum Dangeard (1927a) 

P. parallelum Broch (1906) 

P. saltans Meunier (1910) 

P. antarcticum Schimper (Karsten, 1905) 



16 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



P. claudicans Paulsen (1907) 

P. polymorphum Lindemann (1924) 

P. oceanicum VanhOffen (1897a, 1897b) 

P. oceanicum f. arupinense Broch (1910b) 

P. oceanicum var. parvulum Mangin (1913) 

P. oblongum Aurivillius (1898) 

P. oblongum var. symmetricum Dangeard (1927a) 

P. oblongum var. inaequale Dangeard (1927a) 

P. oblongum var. latidorsale Dangeard (1927a) 

P. obliquum Dangeard (1927a) 

P. murrayi Kofoid (1907) 

P. murrayi var. occidentals Pavillard (1931) 

P. murrayi var. orientale Matzenauer (1933) 

In the present report only those forms occurring in 
the Carnegie collection are treated. They are: 

P. depressum Bailey 

P. depressum var. parallelum Broch 

P. depressum var. rectius n.var. 

P. depressum var. convexius n.var. 

P. depressum f. bisintercalares n.f. 

P. depressum f. multitabulatum n.f. 

P. claudicanoides n.sp. 

P. oceanicum Vanhoffen 

P. oceanicum var. tenellum n.var. 

P. oceanicum f. spiniferum n.f. 

P. oceanicum f. bisintercalares n.f. 

P. oceanicum f. tricornutum n.f. 

Methods of stud y. The first well-considered clas- 
sification of the Peridinium depressum group was based 
on the principles outlined by Jorgensen (1913) for the ge- 
nus as a whole. This classification presupposes a sta- 
bility in the number and arrangement of the major plates 
of the theca. The inadequacy of the last assumption 
when applied to the Peridinium depressum group will be 
clear from the following historical review and consider- 
ation. 

Jorgensen (1913) described the genus Peridinium as 
having the following pattern: 4ap, 3a, 7pr, 5po, 2ant. 
Lebour (1925) and Paulsen (1931) broadened the concept 
of the genus. They included JOrgensen's Archaeperidi - 
nium, which has only two intercalary plates, and divided 
the genus into two subgenera: Peridinium with three, 
Archaeperidinium with two intercalary plates. In the 
present investigations, forms in the section Oceanica of 
the subgenus Peridinium were found with only two inter- 
calary plates (pp. 21, 24); and Dangeard (1927b) report- 
ed a variety with only one intercalary (see next para- 
graph). Thus, this subgeneric character has been shown 
invalid. 

From the Peridinium depressum group the follow- 
ing examples of plate variation may be given. Barrows 
(1918) described a specimen of P. oceanicum . which is 
closely related to P. depressum , with the ventral epithe- 
cal plates of the Paraperidinium type. Dangeard (1927b) 
described what he called a variety of P. depressum with 
the ventral epithecal plates of Paraperidinium and the 
dorsal plates of the section Pyriformia . Considering 
the body form and the inclined girdle of this specimen, 
along with its plate pattern, it is either a distinct vari- 
ety or a species, unquestionably belonging to the group 
related to P. depressum . Dangeard (1927b) also de- 
scribed some aberrent plate patterns in P. oblongum . 
These variants he designated as varieties, as follows: 
var. symmetricum . with the usual dorsal epithecal pat- 
tern of the section Oceanica ; var. inaequale, with the 
pattern of the section Tabulata ; and var. latidorsale , 
with only one intercalary plate (subgeneric character). 
This single intercalary plate borders plates 2pr, 3pr, 



4pr, and 5pr according to his figure. In his table (p. 11) 
he states that it also borders plate 6pr. 

Barrows (1918) was of the opinion that there are 
only four unstable areas in the theca of Peridinium . 
Variation, he maintained, occurs only in the areas at the 
two sides of the first apical, and at the sides of the sec- 
ond intercalary along with the adjacent plates involved 
in any pattern. Other variable areas, however, were 
found later. Peters (1928) described two patterns in P. 
depressum in regard to the epithecal plates. 

The variation on the lateral sides of the epitheca in- 
volves plates 2ap, 2pr, la, and 3pr on the left side and 
4ap, 6pr, 3a, and 5pr on the right side (fig. 9). The var- 
ious patterns will be referred to in the pages to follow 
as the first and second symmetrical, and the first and 
second asymmetrical patterns. In the first symmetri - 
cal pattern , 2ap touches 3pr, and 4ap touches 5pr (fig. 
9A). In the second symmetrical p attern , 2pr touches la, 
and 6pr touches 3a (fig. 9B). In the first asymmetrical 
pattern . 2pr touches la but 4ap touches 5pr (fig. 9C). In 
the second asymmetrical pattern , 2ap touches 3pr but 
6pr touches 3a ffig. 9D). 

Peters (1928) reports all four of these patterns in 
P. depressum . Lindemann's (1925, figs. 10, 11) figures 
of P. marinum (=P. depressum ) show the first symmet- 
rical and the first asymmetrical patterns. In the Car - 
negie material they were not all found in the same spe- 
cies. In P. depressum the first symmetrical and first 
and second asymmetrical were found; in P. oceanicum 
the first symmetrical and first asymmetrical; in P. 
claudicanoides the second symmetrical and first asym- 
metrical. 

These patterns are not stable features of the theca. 
The length of the critical sutures between the four plates 
in question on each side of the shell varies. In species 
where more than one pattern occur, there is an inter- 
gradation of the different patterns. Specimens occur in 
which the edges of the four plates meet at a common 
point, representing an intergrade between two patterns. 
Lebour (1925, pi. 23d) shows this condition on both sides 
of the theca, but this may be an error in drawing. Pe- 
ters (1928) found the common intersection on each side 
of the theca in different specimens. In the Carnegie ma- 
terial this condition was found only in P. depressum and 
only on the left side (fig. 9E). These observations upset 
Barrow's contention that the edges of four plates never 
meet in a common point and that an intergradation never 
occurs between two alternate plate patterns (1918, pp. 
453, 455). 

In order to study this intergradation and present it 
graphically, measurements were made of the critical 
sutures in species in which the first symmetrical and 
first asymmetrical patterns occur. The following com- 
putation was made: The length of the critical suture on 
the left side was divided by the length of the critical su- 
ture on the right side and the quotient called the x- ratio . 
In the symmetrical pattern the ratio was considered a 
positive quantity and in the asymmetrical a negative 
quantity. Obviously, in the case of the intergrade pat- 
tern (fig. 9E) the ratio was zero. 

The x- ratio was computed for 144 specimens of P. 
depressum, P. oceanicum , and varieties selected at ran- 
dom. The ratios were grouped into 0.10 unit classes and 
the frequency of the classes plotted (fig. 10). It is evident 
that in the Carnegie material the symmetrical was the com- 
moner pattern, occurring in about 87 per cent of the 
specimens. The commonest x-ratios were from +0.5 to 



FAMILY PERIDINIACEAE 



17 



+ 1.0. Two intergrades were found in these random sam- 
plings, represented by the two specimens with x- ratios 
of 0.0. In the symmetrical pattern the critical suture on 
the left side varied from to 1.6 times as long as the 
one on the right side; in the asymmetrical pattern the 
alternate suture varied from to 0.9 times the one on 
the right side. 

These observations show definitely that p late pat - 
tern in this group of species is not a stable feature but 
that there is a variation both in the length of the sutures 
and in the relative position of the plates, and that be- 
tween two patterns there is a continuous line of inter- 
grades. 

Thus, it is evident that the epithecal plate pattern 
alone cannot be used for the classification of the species 
related to P. depressum and that it must be used with 
considerable discretion in other parts of the genus as well. 

The hypothecal pattern is constant throughout the 
genus, so that it, too, cannot be used. In the present in- 
vestigations the tabulation of the ventral area was stud- 
ied. Although it differs greatly in different parts of the 
genus, it was found to be identical throughout the "For- 
menkreis P. depressum ." Thus, the plate pattern of no 
part of the theca is of any value in classifying the units 
of the group now under consideration. 

For this reason, a new method had to be devised for 
this purpose. In order to determine whether or not spe- 
cific and varietal segregations can be made on the basis 
of body shape, the material in the Carnegie collection 
related to P. depressum was studied from this stand- 
point. The results showed that the "Formenkreis P. de- 
pressum" is made up of several units, some of specific 
value, others of varietal, and that these are expressed 
by the shape of the body. 

In order to make proper segregations on the basis 
of body shape, it is necessary that this feature be de- 
scribed by numerical expressions so that the frequency 
of variations can be plotted. In order that the accumu- 
lated information of the various workers may be com- 
parable, these numerical expressions must be of a stand- 
ard nature. For instance, the conclusions in the present 
work stand partly in opposition to those arrived at by 
Peters (1928). Even though this is in most part due to 
the different material used, it is probably also due to the 
different methods employed in measuring the body pro- 
portions. For this reason, the proposed standard meth- 
ods for orienting and measuring the specimen described 
above (pp. 1, 2, 13) were used in this work. 

When numerical expressions are used, a large num- 
ber of specimens can be measured, the body proportions 
computed, the values grouped into convenient classes, 
and the frequency of these classes plotted. In the inter- 
pretation of the frequency diagrams, it is necessary to 
have in mind a standard expression of the species con- 
cept. The following definitions of the various units have 
been used in this report. 

It is assumed that a species represents a group of 
ii.uividuals which is morphologically distinct or nearly 
so in one or more features. The presence of inter- 
grades in a very small proportion of the specimens is 
not considered to vitiate the specific segregation. Var- 
ieties may be considered incipient species which also 
have a certain morphological distinctness but which are 



connected with the main species by a higher proportion 
of intergrades. Forms are considered as temporary 
expressions due either to internal or to environmental 
causes. They are characterized by rarity of occur- 
rence. These are the main concepts which have been 
used in the classification of the Carnegie material given 
below. 

Example of application of method . The first prob- 
lem in the "Formenkreis" to be attacked by the statis- 
tical method was the determination of the validity of P. 
oceanicum VanhOffen as a specific unit. 

Vanhoffeh (1897a) figured P. oceanicum as a spe- 
cies similar to P. depressum but longer and more slen- 
der. This was accepted as a valid species by most au- 
thors. Peters (1928), the only previous investigator to 
make a numerical study of the body proportions in this 
group, took exception to this. On the basis of antarctic 
material and of one sample of North Sea material, he 
concluded that P. oceanicum represents simply one end 
of a line of variation which includes both P. depressum 
and P. oceanicum , although he recognized "broad ' and 
"slender" forms. 

In the present investigations 170 random specimens 
of the "Formenkreis" from widely scattered Carnegie 
stations in the North Atlantic were measured and the 
h/d ratios computed. The frequencies of the length, 
width, and h/d classes were plotted as shown in figures 
11-13. As is apparent from figure 11, this group of 
specimens was homogeneous so far as length was con- 
cerned. Some length classes were somewhat more com- 
mon than others, but they were all connected by numer- 
ous intergrades. There was no indication of separated 
variation groups. Similar results were obtained in a 
study of the frequency of the diameter classes (fig. 12). 
This indicated an even more unified group except for the 
small group at the 70-micron and 75-micron classes, 
which further observation of the material failed to jus- 
tify as a distinct, unit. 

The diagram of the plotted frequencies of the h/d 
ratios, however, indicated two variation groups (fig. 13). 
One centered about the 0.90-unit class, the other around 
1.35. The extremes of the first group ranged from 0.65 
to 1.20 and of the second group from 1.20 to 1.75. 

We have here a basis for assigning specific values 
to two forms: a broad form, P. depressum , in which the 
h/d ratio is less than 1.20; and a slender form, P. oce - 
anicum , in which that ratio is more than 1.20. Any spec- 
imen with an h/d ratio of about 1.20 must be considered 
a transitional form between the two species. One such 
was found in the above samplings, as indicated in the 
diagram. It must also be concluded, therefore, on the 
basis of the above studies, that these two species are 
very close. Indeed, more extended studies of other ma- 
terial may bring them closer than is indicated by the 
above data. 

It is clear from these studies, however, that we are 
not dealing here with a single homogeneous group, and 
that P. oceanicum does not represent simply one end of 
a line which includes both P. depressum and P. oceani - 
cum . as Peters (1928) contended. 

The further application of this statistical method in 
this group will be taken up in the discussions under the 
particular species. 



18 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Peridinium depressum Bailey 
(Figure 14) 

Peridinium depressum Bailey, 1855, pp. 12-13, pi. 

figs. 33, 34. Jorgensen, 1899, p. 36, tabs. 4, 18, 30, 
44, 58, 72. Ostenfeld, 1900, p. 57, tabs. 2-7. Cleve, 
1900b, p. 257. Jorgensen, 1901, p. 34. Gran, 1902, 
pp. 186, 191-192. Jorgensen, 1905, p. 109. Van 
Breeman, 1905, p. 43. Broch, 1906, pp. 151-157, 
fig. 1. Paulsen, 1907, pp. 11, 15. 1908, pp. 39, 53, 
fig. 67. Broch, 1908, p. 5. 1910, pp. 51-52, fig. 26. 
Meunier, 1910, p. 27. Paulsen, 1913, pp. 276-279, 
pi. 46. Mangin, 1913, pp. 158-160, 162-164,166- 
169, 171, 177-178, 180, 187, 220-222. fig. 9, tabs. 
1-3. Jorgensen, 1913, pp. 5-6. Forte, 1922, pp. 89, 
188, 207. Lebour, 1925, p. 119, pi. 23, figs. a-f. 
Dangeard, 1926, p. 322, fig. 10. Dangeard, 1927b, 
p. 2, figs. 1A-1C. Paulsen, 1930, pp. 55, 68. Pavil- 
lard, 1931, pp. 55, 64-65, 111-112, 114-115, 121, 
123, 125, 127, 129, 131, 133, 137, 157, 159, 161, 165, 
169, 173, 177, 183, 185, 191, pi. 2, figs. 6A-6E. 
Gran, 1933, pp. 162, 180. 

? Peridinium divergens y reniforme Ehrenberg, 1854, 
p. 240. Meunier, 1910, p. 23, pi. 1, figs. 1-4. 

Ceratium divergens Claparede and Lachmann, 1861, p. 
71, pi. 13, fig. 23. 

Peridinium divergens , Bergh, 1881, pp. 63, 67, 70, 73. 
Bergh, 1882, pi. 15, fig. 45. ? Stein, 1883, pi. 11, 
figs. 1, 2. Vanhoffen, 1897a, pp. 267-268, pi. 5, fig. 

1. Cleve, 1900a, figs. 15, 16. Meunier, 1910, pi. 2, 
figs. 45, 46. Lebour, 1917, p. 186. Meunier, 1919, 
pp. 12-14, pi. 15, figs. 1-5. 

Peridinium divergens vari£te, Pouchet, 1883, p. 40, pis. 

20, 21, fig. 23. 
Peridinium divergens var. reniforme , Pouchet, 1883, p. 

40, pis. 20, 21, figs. 24-27. 
not Peridinium divergens var. typus , Pouchet, 1883, p. 

38, pis. 20, 21, figs. 20, 21. Ostenfeld, 1899, p. 60, 

84, tabs. 1-8. 
Peridinium divergens var., Schfitt, 1895, pi. 13, figs. 

43 (22), 43(24). Meunier, 1910, pi. 1 (bis), figs. 1, 

2, 7, 8. 

Peridinium divergens var. depressa , Aurivillius, 1898, 

p. 55. Ostenfeld, 1899, pp. 60, 70, 86, tabs. 1-8. 
Peridinium elegans Cleve, 1900a, in part, pi. 7, fig. 16. 
Peridinium depressa , Ostenfeld, 1900, tab. 1. 
Peridinium divergens var. depressum , Karsten, 1907, 

p. 466. 
Peridinium kofoidii Faure-Fremiet, 1908, pp. 224-226, 

fig. 11, pi. 16, fig. 12. Mangin, 1913, p. 222. 
Peridinium marinum Lindemann, 1925, pp. 98-99, figs. 

7-11. 
Peridinium marinum var. travectum Lindemann, 1925, 

p. 99, fig. 12. 



Dimensions . Length of body ( 1) 187 (114-228) mi- 
crons; diameter (d) 137 (108-160) microns. Width of 
girdle, about 7 microns. Eighty specimens were meas- 
ured. 

Shape . Length of body, exclusive of antapical horns, 
normally equal to diameter of body at girdle as shown 
by the h/d ratio, which is 1.00 (0.77-1.18). The angle ct 
is 95° (78°-105°). The a/d ratio is 0.39 (0.21-0.65); that 
is, length of right antapical horn normally about 0.4 
times width of body at girdle. The b/a ratio is 0.14 
(0.08-0.27); that is, right antapical horn normally about 
0.14 times as thick as long. 

Cell body very asymmetrical. Roughly, the mid- 
body is a lenticular mass depressed along an anteroven- 
tral-posterodorsal axis running at an angle of about 55° 
to plane of girdle. Epitheca tapers abruptly on lateral 
and dorsal faces, but gradually on ventral side, into an 
apical horn which extends along an axis which lies at an 



angle of about 65 ° to the axis of depression of mid-body. 
Hypotheca terminates in two antapical horns which are 
pointed and more slender than the apical horn. Right 
antapical horn may lie parallel to axis of apical horn, 
but usually diverges somewhat laterally to the right. 
The left one is shorter than the right and diverges from 
it laterally and ventrally. The girdle leaves the sulcus 
on the left side of the body, curving forward to a point 
about halfway to the left side of body, where it begins to 
turn gradually backward. This backward curvature is 
continued entirely around the body, so that the distal 
end of the girdle terminates on the right side of the sul- 
cus from 1.5 to 2.5 girdle widths behind the proximal 
end. This does not represent the maximum displace- 
ment of the girdle, however, which occurs between the 
distal end and the front of the curvature to the left of the 
sulcus. This displacement is about 3 girdle widths. 
The displacement of the girdle can be seen only when 
the specimen is viewed ventrally. When the specimen 
is allowed to come to rest in a drop of water on its pos- 
terodorsal surface, a position commonly represented in 
published figures, no displacement of the girdle is evi- 
dent (fig. 14A). Girdle not concave. Body reniform in 
apical or antapical view, with the indentation at sulcus. 
The g/d ratio, about 0.75. Ventral area narrow, with 
more or less parallel sides, 2.0 to 2.5 girdle widths 
wide. Sulcus proper deeply embedded, extending to ant- 
apex. Anteriorly the ventral area extends very slightly 
beyond proximal end of girdle. 

Plate pattern . The first symmetrical and first a- 
symmetrical patterns occurred in the proportion of a- 
bout 4 to 1. The frequency distribution of the two pat- 
terns is shown in figure 10. 

The apical horn terminates in a more or less trun- 
cated apex, about 8 microns in diameter. This region is 
much more complex than was at first supposed. It is not 
formed simply by the apical ends of the four apical 
plates. In fact, the first apical plate ("rhomboid plate" 
of Kofoid or "Rautenplatte" of Butschli) does not extend 
entirely to the apex. The first apical, or rhomboid, 
plate terminates about 9 microns below the apex, where 
it borders on a narrow ventral apical platelet (v. a. p., 
fig. 15) which extends to the apex. This platelet is al- 
most rectangular in outline, about 9 microns long and 
slightly more than 2 microns wide. Its posterior end is 
convex, where it fits into an equivalent concavity in the 
anterior end of the rhomboid plate. This convexity may 
be slight or, in some cases, extreme. Since the rhom- 
boid plate does not reach the apex, it is not an apical 
plate, strictly speaking. It seems desirable, however, 
to retain the term "first apical" for this plate because 
the ventral apical platelet is extremely small and per- 
haps not equivalent to the other apicals. The possibili- 
ty of the homology of this platelet with the major plates 
of the other genera, however, should not be overlooked. 

The exterior of the apex is formed by the ventral 
apical platelet on the ventral side and the anterior ends 
of the second, third, and fourth apical plates on the left, 
dorsal, and right sides, respectively. The joining of 
these plates is strengthened interiorly by a pore plate- 
let, sleevelike in form, around which the ends of the ex- 
terior plates fit snugly. This apical pore platelet (a.p.p., 
fig. 15) is about 5 microns in diameter and 3 microns 
long. Its walls are about 1.5 microns thick, so that the 
apical pore, representing the bore of this sleeve, is a- 
bout 2 microns in diameter. 

The girdle is composed of four plates (lg-4g, fig. 



FAMILY PERIDINIACEAE 



19 



16). The first g irdle plate (ig) is a short plate, about 5 
microns long, at the proximal end of the girdle, where 
it borders the anterior plates of the ventral area. The 
second g irdle plate (2g) extends from Ig between plates 
Ipr and lpo, as far as the lateral edges of the latter 
plates, so that the suture 2g/3g is continuous with the 
sutures lpr/2pr and lpo/2po. The third girdle plate 
(3g) is very long and runs completely around the dorsal 
side of the body to a corresponding suture on the right 
ventral side at the lateral edges of plates 7pr and 7po. 
The fourth girdle plate (4g) runs from 3g to the right 
side of the sulcus forming the distal end of the girdle. 

The skeletal structure of the ventral area is very 
complex as compared with the skeletal composition of 
the rest of the body. Externally the sulcus is composed 
of five plates (figs. 17, 18; pi. 1, figs. A, B). The ante - 
rior sulcal plate (a.s.) is at the right anterior end of the 
ventral area. Its anterior end runs slightly into epithe- 
ca above proximal end of girdle; posteriorly it expands 
and forms the anterior edge of flagellar pore. The left 
sulcal plate (l.s.) composes most of left side of sulcus. 
Its right edge forms the left edge of flagellar pore. The 
posterior sulcal plate (p.s.) is a narrow, roughly U- 
shaped plate constituting posterior end of sulcus. The 
right sulcal plate (r.s.) occupies right side of sulcus and 
its left edge forms right edge of flagellar pore. 

From both the anterior and posterior edges of the 
flagellar pore, there extend into the cell body two inter- 
nal processes, the anterior pore process (a. p. p.) and the 
posterior pore process (p. p. p.). These processes (figs. 
17B, 18A, B) are curved in cross section so that they 
form grooves running into the cell body, apparently 
forming supporting structures for the two flagella which 
emerge from the cell body at the flagellar pore. The 
anterior pore process is constructed principally of an 
internal extension of the posterior edge of the anterior 
sulcal plate. On the right side, it is tied to the right 
sulcal plate by the right internal sulcal p late (r.l.s.), 
which runs along the entire right edge of the process, 
and posteriorly along the left interior edge of the right 
sulcal plates, and part way along the posterior pore 
process. Along its entire course it is underlaid by a 
membrane (m) attached to its adjacent plates. The left 
side of the anterior pore process is formed in part by 
the anterior groove list (a.g.L), which also extends part 
way along the external portion of the anterior sulcal 
plate. The groove in the posterior pore process, as it 
comes to the surface, runs posteriorly to the end of the 
sulcus. The internal portion of this groove, i.e., the 
posterior process, is formed on the right side princi- 
pally by an extension of the right sulcal plate. The pos- 
terior and left sides are formed by a separate plate, 
the posterior accessor y sulcal plate (p. a.s.). Wherethe 
posterior groove runs along the exterior, however, it is 
overlaid by a listlike process originating from the sides 
of the posterior and right sulcal plates, the p osterior 
groove list (p.g.l.). The exterior extension of the pos- 
terior groove is open on the left side but covered ven- 
trally by this list (figs. 17, 18C; pi. 1, figs. A, B). 

The right edge of the flagellar pore is bounded by 
the right accessor y sulcal list (r.a.s.), which is attached 
along the edge of the right sulcal plate. In its posterior 
portion it joins with the posterior groove list. 

A cross section of the right sulcal plate (fig. 18D) 
shows the curvature of that plate as well as the relative 
position of the right accessory sulcal list and the mem- 
brane to which the right internal plate attaches. 



Thecai wall . Surface of plates sculptured with ir- 
regular reticulation which is difficult to demonstrate, 
except at intersections, where it is raised into irregu- 
lar points. 

Pores occur throughout all major plates, irregu- 
larly scattered and bearing no relation to reticulations; 
absent in girdle plates. 

Boundaries between plates vary from simple su- 
tures to wide intercalary zones. Rabbet joints present 
in all parts of theca (see p. 10). Intercalary zones and 
rabbet membranes occur in tne girdle at the 2g/3g and 
the 3g/4g sutures corresponding to the similar struc- 
tures in the plates of the epitheca and hypotheca adja- 
cent to the girdle (fig. 16A). 

Lists . Cingular lists 8 to 10 microns wide, usually 
somewhat broader at the left ventral side. They are 
strengthened at the base by short ridges which connect 
with similar strengthenings in the girdle and body plates, 
and at the outer edge by ridges which extend about half- 
way to the center of the list (pi. 1, fig. A). 

The apical list (fig. 15; pi. 1, fig. C) encircles the 
apex dorsaily and laterally, but ventrally it runs down 
each side of the ventral apical platelet and extends part 
way down the sides of the first apical plate. It forms a 
collar around the apex about 2 microns in height, slight- 
ly funnel-shaped with serrated edge. Toward the poste- 
roventral ends, the list diminisnes in width gradually 
and terminates on each side of the first apical plate a- 
bout 5 microns below the anterior end of that plate. Lat- 
erally, from tne apex, there is a list on each side which 
runs from the apical list posteriorly. The right lateral 
list (r.1.1.) extends down the suture between the third 
and fourth apical plates, and the left lateral list (1.1.1.) 
extends down the suture between the second and third 
apicals. These lists are of the same width as the apical 
list near the apex, but narrow gradually and end at points 
about two-thirds of the way down the third apical plate. 
The origin of the apical and lateral lists is not as might 
be expected from a study of an intact specimen. Separa- 
tion of the apical units, as shown in figure 15B, demon- 
strates the attachment of the lists. The apical list is 
composed of three parts: the dorsal, right, and left seg- 
ments. The dorsal segment of the apical list (d.l.) and 
the lateral apical lists are continuous and are attached 
to the third apical plate along its anterior and lateral 
edges. The left segment of the apical list (l.a.l.) with 
its continuation down the ventral side of the horn is at- 
tached to the second apical plate along its anterior and 
anteroventral edges. The right segment of the apical list 
(r.a.l.) with its continuation down the ventral side of the 
horn is attached to the fourth apical plate along its an- 
terior and anteroventral edges. 

In an intact specimen it is difficult to see the apical 
list except where one looks through considerable thick- 
ness of the list in the arcs which are tangent to the lines 
of vision. It thus appears as two spines in whatever 
longitudinal view the specimen is observed. This ex- 
plains the real nature of the prominences which are fre- 
quently shown in figures of this species. 

The more carefully drawn figures of this species 
have shown that the first apical plate terminates below 
the apex, but the space anterior to it has been indicated 
as a separation continuous with the apical pore. This 
space, as is now shown, is occupied by the ventral api- 
cal platelet. 

The ventral area is almost entirely bounded by a 
system of lists which are attached to the body plates 



20 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



surrounding the area. On the left side a wide list, the 
left sulcal list (1.1.), runs along the first postcingular 
plate (to which it is attached) to the suture between this 
plate and the first antapical plate. This list is a contin- 
uation of the posterior cingular list. The posterior sul- 
cal list (p.l.) extends from the above suture around the 
posterior end of the sulcus to the suture between the 
second antapical and the fifth postcingular plates. It is 
attached to the sulcal edges of the two antapical plates. 
Where this list turns from the sides of the sulcus down 
to the posterior end, it runs parallel with the line of 
vision when the specimen is viewed ventrally. When 
viewed on an intact specimen, this list is visible fre- 
quently only at the posteroventral corners of the sulcus, 
where considerable thickness of the upturned list results 
in greater interference of light and gives the impression 
of two spines. Specimens have often been figured with 
these two "spines" at the bases of the antapical horns. 
The posterior right sulcal list (p.r.l.) extends from the 
posterior cingular list to the suture between the fifth 
postcingular and second antapical plates. It is attached 
to the former plate and is continuous with the posterior 
cingular list. The right and left sulcal lists, when seen 
from the apical or antapical ends, appear as two spines 
near the ends of the cingular lists and have frequently 
been so drawn or referred to as "teeth" at the base of 
the antapical horns. The anterior right sulcal list 
(a.r.l.) is a structure of the epitheca. It borders the 
right edge of the sulcus which extends into the epitheca, 
but is attached to the sulcal edge of the seventh precin- 
gular plate and is continuous with the anterior cingular 
list. 

Variation . There is variation in the habitus of the 
species, as can be seen from the specimens presented 
in figure 19. It should be noted that the differences in 
the habitus of these specimens are due chiefly to the 
variations in the length, thickness, and degree of diver- 
gence of the antapical horns, and in the length of the 
apical horn. That the pronounced differences in the 
shape of the mid-body which are suggested by this fig are 
are more apparent than real, was demonstrated by pro- 
portional measurements of the specimens. These meas- 
urements all fell within the limits of the species (p. 16). 

For variation in the plate pattern, see p. 14. The 
tabulation of the ventral area and girdle is constant. 

Comparisons . The species of the "Formenkreis" 
P. depressum comprise the greater part of the section 
Oceanica of Orthoper idinium . They can be distinguished 
from the other species of the section by the inclined gir- 
dle. Also, the other species are mostly much smaller, 
e.g., P. obtusum Karsten and P. bulla Meunier. 

Within the "Formenkreis," P. depressum can be 
distinguished from the other species by its body shape. 
It is very similar to P. oceanicum (see p. 15), but can be 
distinguished from the latter by its lower J/d ratio 
(less than 1.20) and lower angle a. (less than 105°). 

Peridinium claudicanoides n.sp. of this "Formen- 
kreis" can be separated from P. depressum by its cune- 
ate antapical horns and by its b/a ratio, which is great- 
er than 0.23. 

Historical . Bailey (1855) described and figured P. 
depressum in an easily identifiable manner. Some early 
authors, e.g., Pouchet (1883) and Cleve (1900b), consid- 
ered this form to be identical with P. divergens Ehren- 
berg (1840). Others, e.g., Bergh (1881) and Meunier 
(1910), were somewhat more discriminating and consid- 
ered P. depressum to be identical only with the variety 



which Ehrenberg (1854) described as P. divergens y 
reniforme . It is possible that this variety and P. de- 
pressum are identical, but since the figure of Ehrenberg 
(p. 240) cannot be identified with any measure of cer- 
tainty, and since Bailey's figures are readily recogniza- 
ble, it is advisable to retain the now universally accept- 
ed name depressum for this species. 

Since the importance of the plate pattern in the clas- 
sification of the species of this genus was not realized 
until the present century, and since neither Ehrenberg 
nor Bailey indicated the tabulation for the two species in 
question, considerable confusion developed regarding 
these forms. There was even a tendency to lump all 
large forms of Peridinium under one species, viz., P. 
divergens Ehrenberg, which was the first to be described 
in the genus. 

After Broch (1910) and JOrgensen (1913) had demon- 
strated the importance of tabulation in this genus, it be- 
came necessary to determine the plate patterns of the 
various species which had been described earlier. 

In the case of P. depressum this was not difficult, 
as the figures of Bailey are easily identifiable. This 
form has the Orthoperidinium tabulation, one which was 
first indicated for this species by Pouchet (1883, pi. 21, 
fig. 26) under the name of P. divergens var. reniforme . 

In the case of P. divergens , it is impossible to es- 
tablish the tabulation except on an arbitrary basis, since 
neither the description nor the figures of Ehrenberg are 
identifiable. The first figures of tabulation shown under 
the name of P. divergens are those of Stein (1883), but 
unfortunately, as Lebour (1925) states, Stein figured at 
least three species under this name. It is not difficult, 
however, to select figures 2 to 6 of plate 11, as those 
which are most likely to represent Ehrenberg's P. di- 
vergens. For the sake of clarifying the confused synon- 
ymy of this species, these figures should be accepted, 
as Lebour suggested, as establishing the tabulation of P. 
divergens . The pattern is that of the section Divergens . 
Metaperidinium , of J5rgensen. 

The specific distinctness of P. depressum and P. 
divergens has been fully realized by most workers in 
this field for a considerable period. Meunier, as late 
as 1919, figured P. depressum under the name of P. di- 
vergens; however his argument to discard the former 
name seems invalid. 

Peridinium kofoidii , described by Faure-Fremiet 
(1908), is undoubtedly a long-horned form of P. depres - 
sum with roughened antapicals. The apical view shows 
only three apical plates, but this is probably an error in 
drawing, for the dorsal apical plate is difficult to dem- 
onstrate in this view. 

Distribution . Very common in the boreal Atlantic 
Ocean (Paulsen, 1908; Lebour, 1925) and in the Antarc- 
tic (Karsten, 1905; Peters, 1928). Matzenauer (1933) 
found it frequently in the Indian Ocean and Forti (1922) 
in the Mediterranean. Bohm (1936) reported it from the 
Pacific between Hong Kong and Shanghai, where its oc- 
currence was sporadic. It is apparently a cosmopolitan 
species having centers of abundance in the cooler re- 
gions of both hemispheres. 

In the Carnegie collection this species was found at 
35 stations: 22 in the Atlantic, 13 in the Pacific. There 
are 72 records of occurrence: 34 rare, 28 occasional, 
6 common, and 4 abundant. It was found about equally 
at the three levels, with 20 records for the surface, 17 
for 50 meters, and 20 for 100 meters. There are 48 net 
records and 24 pump records. It was found only in the 



FAMILY PERIDINIACEAE 



21 



northern hemisphere and in the months from May to Sep- 
tember. 

The Carnegie records exhibit a very curious distri- 
bution, being widely scattered in the Atlantic but limited 
in the Pacific (fig. 20). In the Atlantic the species oc- 
curred from north of the Faeroes Islands as far south as 
latitude 13 °4 north. Its center of abundance was the 
Grand Banks of Newfoundland, where it occurred in enor- 
mous numbers clogging the collecting nets, particularly 
at 50 and 100 meters depth. In the Pacific it was re- 
stricted to a line of stations off Japan and the western 
Aleutian Islands, stations 111 to 122. 

This species was found in a great range of hydro- 
graphic conditions. The surface temperatures at the 
stations where it occurred at any depth varied from6°9 
to 27°6 C. The ranges of hydrographic conditions in situ 
were as follows: temperature, -l.°6 to 26.°7 C; salinity, 
32.7 to 37.2 o/oo; pH, 7.86 to 8.27; phosphate, 3 to 184 
mg P04/m3. 

It is obvious from the above data that the factor lim- 
iting the distribution of P . depressum has not yet been 
identified. Considering the varied conditions under 
which the species was found in the Atlantic, it is diffi- 
cult to explain its peculiarly restricted distribution in 
the Pacific unless its occurrence is normally sporadic, 
as Bohm (1936) indicated was the case in the southwest- 
ern Pacific. 

It is of interest to note that the species exhibited its 
greatest variation in the region of the Grand Banks of 
Newfoundland (station 13), where conditions were ex- 
treme. In this region the surface temperature was 11°27, 
whereas at 25 meters 0°.75 was recorded. At 50 meters 
the temperature was only -1°64 and at 100 meters 1°.10. 
Curiously enough, the richest collection of P. depressum 
made by the Carnegie was at the Grand Banks station at 
50 meters. It cannot be concluded that low temperatures 
are favorable to this species, because it is quite possi- 
ble that the production of this population occurred at a 
higher level. It at least indicates that P. depressum can 
endure low temperatures. The species seems to be eu- 
rythermal to a high degree, for it was again found in the 
tropics at temperatures as high as 26 °7. South of sta- 
tion 15 (latitude 39° north), however, it was always 
found below the surface, a fact which may have been due 
to the higher temperatures prevailing at the surface. It 
should be noted that the higher concentration of nutri- 
ents which occurs below the surface in the warmer wa- 
ters may have been responsible for this distributional 
peculiarity. 

Since the species has a distribution which cannot be 
correlated with any known hydrographic condition, it is 
at present of no value as an oceanographic indicator. 



Peridinium depressum var. parallelum Broch 
(Figures 21, 22) 

Peridinium parallelum Broch, 1906, pp. 153-157, fig. 2. 

Paulsen, 1907, pp. 11, 15; 1908, pp. 39, 54, fig. 68. 

Broch, 1908, p. 5. Broch, 1910, p. 52. Mangin, 1913, 

p. 221. Paulsen, 1913, p. 279, pi. 47. Pavillard, 

1931, pp. 56, 114-116,121, 123, 159, 161, 163, 167, 169, 

175, 183, 185, 187, pi. 2, fig. 7A, B. 
Peridinium divergens var. Schiitt, 1895, pi. 13, fig. 

43 (23). Meunier, 1910, pi. 1 (bis), figs. 3, 4. 
Peridinium antarctlcum Schimper in Karsten, 1905, pp. 

37, 38, 40, 43-51, 53-57, 59-61, 64-68, 131-132, pi. 

19, figs. 1-4. Broch, 1906, p. 153. Paulsen, 1931 

p. 55. 



Peridinium depressum subsp. parallelum Broch, 1906, 

p. 151. 
Peridinium divergens antarcticum . Karsten, 1907, pp. 

225, 416. 

Dimensions . Length of body (1) 132 (100-160) mi- 
crons. Diameter of body (d) 120 (94-138) microns. 
Forty-nine specimens were measured. 

Shape. This variety is usually more rotund than 
the main species, with short and slender antapical 
horns, frequently solid part way or entirely to the base, 
usually straight and parallel. The h/d ratio is 0.84 
(0.73-0.96). The a/d ratio is 0.24 (0.16-0.29). The b/a 
ratio is 0.15 (0.10-0.20). The angle ctis 110° (94°-129°). 

Plate pattern . Tabulation of major body plates as 
in P. depressum with addition of second asymmetrical 
pattern found in one specimen. It should be noted that 
the first symmetrical and first asymmetrical patterns 
occurred in about the same proportion as in P. depres - 
sum (fig. 10). Tabulation of girdle and ventral area also 
as in main species. 

Variation and comparisons . Broch (1906) separat- 
ed this variety on the basis of solid antapical horns. 
This is not a good character, however, as Peters (1928) 
has demonstrated. In our material the solidity of the 
horns was a function of the thickness of these struc- 
tures. The thinner horns were solid part way or en- 
tirely to the base. 

The angle a. is low owing to the greater convexity 
and shortness of the body. When the specimens were 
examined, this convex curvature of the body seemed 
characteristic, and in the early part of these investiga- 
tions it was .thought that the variety could be distin- 
guished on the basis of this character alone. When 108 
random specimens of the main species and of var. par- 
allelum were measured, however, and the frequency of 
their angle oc values was plotted, it was found that this 
feature is not specific (fig. 23). Rather than two sepa- 
rate groups, the frequency distribution suggests a ser- 
ies of variable and intergrading units. Since these re- 
sults could not be corroborated by the study of addition- 
al characters, the attempt to separate the variety on 
this basis was abandoned. 

Because of the fact that var. parallelum appeared 
to have shorter horns than P. depressum . a study was 
made of the relative lengths of the antapical horns. The 
a/d ratio, representing the length of the right antapical 
horn in relation to the width at the girdle, was comput- 
ed for 108 random specimens. The values obtained 
were grouped into 0.03-unit classes and the frequencies 
plotted (fig. 24). This study also showed that there is no 
complete separation of two groups. There is an indica- 
tion of two groups, however, intergrading at the a/d 
class of 0.31. This grouping corresponds well to other 
differences in habitus, etc. This was the best numeri- 
cal measure that could be found to delimit var. paral - 
lelum , a fact that clearly shows the uncertain status of 
this unit. 

Since further knowledge of the differences in the 
distribution of these two forms is needed, it is desira- 
ble that the occurrence of the forms be kept separate in 
plankton lists. As shown by the above frequency studies, 
the most effective separation of the variety can be made 
by means of the relative length of the antapical horns. 
In the present work, the a/d ratio of 0.30 was taken as 
the point of separation between P. depressum and var. 
parallelum . 



22 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Historical . Broch (1906) described this form as a 
subspecies of P. depressum Bailey and later (1910a) 
treated it as a distinct species. Paulsen (1908) judged 
it to be a valid species, as did Pavillard (1931) and oth- 
ers. Peters (1928), however, considered it to be com- 
pletely within the variation limits of P. depressum . In 
a study of a vast amount of antarctic material, he stated 
that he found the form always had hollow horns, but in 
one sample from the North Sea he found the horns some- 
times solid and sometimes hollow. In all dimensional 
ratios studied by him he found a variation frequency 
which suggested the presence of only one systematic u- 
nit. He did not consider the a/d ratio, however. 

A form resembling var. paralielum was described 
by Schimper (in Karsten, 1905) as P. antarcticum . Pe- 
ters (1928), who studied both northern and antarctic ma- 
terial, considered these two forms to be identical. Mat- 
zenauer (1933), however, treats antarcticum as a forma 
of P. depressum . Since there is no antarctic material 
in the Carnegie collection, it was not possible to subject 
this southern form to the analysis applied to var. paral - 
ielum , with the result that no direct comparisons could 
be made between the two forms. 

Distribution . Broch (1906) considered this form a 
boreal or boreo- arctic species and stated that in 1905 it 
did not come farther south along the Norwegian coast 
than latitude 62° north. It must be remembered that he 
was considering the solid-spined individuals which prob- 
ably represent the extremes of the variety. Paulsen 
(1908) stated that it occurred as far south as the Skag- 
errack. It occurs in the Antarctic according to Peters 
(1928) and in the Indian Ocean according to Matzenauer 
(1933). The present records are the first for the Pacif- 
ic. 

In the Carnegie collection this variety was found at 
15 stations: 13 in the Atlantic, 2 in the Pacific. There 
are 26 records of occurrence: 8 rare, 11 occasional, 7 
common. It was found about equally at the three levels, 
with 9 records for the surface, 9 for 50 meters, and 8 
for 100 meters. There are 20 net records and 6 pump 
records. It was found only in the northern hemisphere, 
in the months from July to September. 

This variety had a distribution in the Carnegie col- 
lection similar to that of the main species in that it was 
found at widely scattered stations in the Atlantic but was 
restricted in the Pacific (fig. 20). In the Atlantic it was 
found in the North Sea (station 6h), at the stations in the 
region of Iceland, on the line between Iceland and the 
Grand Banks of Newfoundland at all stations except one, 
and as far south as latitude 11° north (station 23). It did 
not occur, however, in a single surface sample south of 
latitude 42° north (station 13a). In the Pacific it was 
found only at two stations, viz., stations 128 and 130, off 
California. 

The variety occurred in a great range of hydro- 
graphic conditions. The surface temperatures at the 
stations where it occurred at any depth varied from8°4 
to 27° 2 C. The hydrographic conditions in situ were as 
follows: temperature, -1°6 to 22°4 C; salinity, 32.7 to 
36.8 o/oo; pH, 7.87 to 8.26; phosphate, 5 to 176 mg 
P04/m 3 . 

It is thus evident that this form cannot be considered 
a strictly low-temperature variety, as Broch (1906) sug- 
gested. It may have its origin and center of greatest 
abundance in the cold regions, but it is highly euryther- 
mal. It is hardly possible that var. paralielum repre- 



sents an ecological variant, since it often occurs mixed 
with P. depressum . 



Peridinium depressum var. rectius n.var. 
(Figure 25) 

Dimensions . Length of body (1) 124 (113-135) mi- 
crons. Diameter of body (d) 84 (76-92) microns. Width 
of girdle about 6 microns. Two specimens were meas- 
ured. 

Shape . Lateral outline in ventral view almost 
straight between girdle and bases of horns. This full- 
ness of body results in high angle oc . The h/d ratio is 
1.10(1.07-1.19). The a/d ratio is 0.38 (0.37-0.38). The 
b/a ratio is 0.17 (0.16-0.18). The angle a is 120° (111°- 
130°). In lateral view the apical horn is continuous with 
the body lines. All horns relatively stout. Lengths of 
antapical horns similar to those in P. depressum , but 
there is little divergence in any direction. Body nar- 
rower dorsoventrally than in P. depressum ; sometimes 
narrow elliptical in apical view (fig. 25A). 

Plate pattern . The epithecal tabulation is of the 
first symmetrical pattern. In our specimens the x-ra- 
tio was +0.6 and +0.7. Tabulation of other parts as in 
main species. 

Body wall . Intercalary zones wide. Plates thinner 
and surface sculpturing much less developed than in 
most specimens of P. depressum . Other details same 
as in main species. 

Comparisons . This variety expresses a tendency 
toward a dorsoventral flattening of the body, and a tend- 
ency toward a loss of the strong depression of the body 
which results in a decrease in the inclination of the gir- 
dle. In all these characters it differs from both the main 
species and var. paralielum . It is further differentiated 
from var. paralielum in its longer and stouter antapical 
horns. It is distinguished from var. convexius , de- 
scribed below, by its straight, instead of conspicuously 
convex, body contours. 

In general appearance var. rectius is similar to P. 
oceanicum var. parvulum Mangin (1913) from Saint - 
Vaast-la-Houge. It differs from this principally in hav- 
ing a low h/d ratio. The h/d ratios computed from 
Mangin's figures range from 1 .24 to 1 .45, which places 
var. parvulum definitely in the P. oceanicum group. 
Furthermore, the sides of var. parvulum are more con- 
vex than in var. rectius . Mangin did not show a side 
view, nor did he state the degree of dorsoventral flat- 
tening. (Fig. 10b, lOd of Mangin are ventral views 
drawn from the dorsal side.) 

Distribution . This variety was found at only two 
stations: stations 6 and 32, both in the Atlantic (fig. 20). 
The former station was southwest of the British Isles 
and the latter in the Caribbean Sea. At the northern sta- 
tion the form was collected with the net at 50 and 100 
meters, in May; at the southern station with the pump at 
the surface, in October. It was rare in each case. The 
ranges of hydrographic conditions at these stations were 
as follows: temperature, 11°3 to 28°0 C; salinity, 35.5 
to 36.0 o/oo; pH, 8.08 to 8.23; phosphate, 2 to 41 mg 
P04/m3. 

The wide range in temperatures indicates that this 
form is eurythermal. Thus, var. rectius is probably a 
rare but widely distributed variety of P. depressum Bai- 
ley. Type locality: Carnegie station 32. 



FAMILY PERIDINIACEAE 



23 



Peridinlum depressum var. convexius n.var. 
(Figure 26) 

Dimensions . Length of body (1) 122 (105-135) mi- 
crons. Diameter of body (d) 81 (76-88) microns. Width 
of girdle about 5 microns. Three specimens were meas- 
ured. 

Shape . Body very convex in ventral view and does 
not flare out in girdle region as in P. depressum . The 
h/d ratio is 1.08 (0.96-1.21). The angle a. is 128° (114°- 
139°). In the girdle region the body is compressed dor- 
soventrally so that it is not so convex in lateral view. 
Theg/d ratio is about 0.70. Antapical horns similar to 
those in P. depressum although somewhat more abrupt- 
ly pointed. The a/d ratio is 0.40 (0.36-0.46). The b/a 
ratio is 0.19 (0.16-0.23). 

Plate pattern . Epithecal tabulation is of the first 
symmetrical pattern. Other parts of theca as in main 
species. 

Comparisons. This variety exhibits a peculiar com- 
bination of features. It shows a tendency toward a 
rounding of the lateral contours of the body as in var. 
parallelum , but retains the horn length of P. depressum . 
There is also a tendency toward a dorsoventral flatten- 
ing, showing a convergence toward the shape of P. de - 
pressum var. rectius and P. oceanicum var. tenellum . 
Variety convexius can be distinguished from P. depres - 
sum by its large angle a; from var. parallelum by its 
longer antapical horns; and from var. rectius by its con- 
vex lateral contours. 

Distribution . This variety was found at 11 stations: 
3 in the Atlantic and 8 in the Pacific. There are 28 rec- 
ords of occurrence: 10 rare, 17 occasional, and 1 com- 
mon. The records were less frequent for the surface; 
there were 5 records for the surface, 11 for 50 meters, 
and 12 for 100 meters. There are 18 net records and 
10 pump records. The variety was found in both hemi- 
spheres, from May to August in the northern, and from 
November to January in the southern. 

In the Atlantic this variety was found at three sta- 
tions, all in or along the Gulf Stream, between longi- 
tudes 46° and 54° west (fig. 20). In the Pacific it oc- 
curred in three regions: (1) off Colombia, station 39; 
(2) in the Humboldt Current, off Peru, stations 69 and 
70; (3) in a series of stations in the region of Japan, sta- 
tions 109-112, 116. 

This form probably has its origin in regions of 
warm water and it does not seem to endure transfer into 
cold conditions. The surface temperatures at the sta- 
tions where it occurred at any depth varied from 16°.l 
to 27 °4 C. The ranges of hydrographic conditions in si- 
tu were as follows: temperature, 6°. 7 to 27°.4 C; salin- 
ity, 33.8 to 36.5 o/oo; pH, 7.68 to 8.23; phosphate, 3 to 
233 mg P04/m3. 

It may be concluded that this is a rare warm-water 
form, sometimes being carried into colder regions. It 
is not common enough to be of value as an indicator of 
the intrusions of water of tropical origin. Type locality: 
Carnegie station 14. 



Peridinium depressum forma bisintercalares n.f . 
(Figure 27) 

Dimensions . Length of body (I) 182 (160-205) mi- 
crons. Diameter (d) 132 (125-140) microns. Width of 
girdle about 5 microns. Two specimens were measured. 



Shape . Body as in P. depressum . The h/d ratio is 
0.98 (0.95-1.02). The angle a is 96° (95°-96°). Length 
and divergence of antapical horns variable. The a/d 
ratio is 0.37 (0.32-0.43). The b/a ratio is 0.12 (0.10- 
0.15). 

Plate pattern . Epithecal tabulation is of the first 
symmetrical pattern except that there are only two in- 
stead of three anterior intercalary plates. In the meas- 
ured specimens the x-ratio was +0.46 and +2.50. 

Comparisons . The distinctive feature of this form 
is the presence of two, instead of three, anterior inter- 
calary plates, a peculiarity also occurring in P. oceani - 
cum (p.24). This pattern is not caused simply by the 
fusion of two of the intercalary plates. Although one 
specimen of P. oceanicum was found that indicated such 
a fusion (p.25), in all other cases some more fundamen- 
tal rearrangement had occurred. The suture between 
the two plates was located medially where no suture 
normally occurs when three plates are present, and the 
dorsal pattern was quite symmetrical. 

Remarks . Since the subgenus Peridinium is founded 
on the presence of three anterior intercalary plates, the 
discovery of the two-intercalary forms in P. depressum 
and P. oceanicum necessitates the revision of the de- 
scription and fundamental classification of the genus. 
This plate pattern was too common in the material stud- 
ied to be passed over simply as "aberrant." It was 
estimated that from 1 to 2 per cent of the specimens of 
P. depressum and P. oceanicum in our material showed 
this pattern, although in the former species it occurred 
only at one station and in the latter at three. 

Distribution . This form was found only at station 
13 at 50 meters on the Grand Banks of Newfoundland in 
August 1928. The hydrographic conditions were as fol- 
lows: temperature, -1°6 C; salinity, 33.4 o/oo; pH, 7.87; 
phosphate, 59 mg P04/m3. Type locality: Carnegie 
station 13. 



Peridinium depressum forma multitabulatum n.f. 
(Figure 28) 

Dimensions . Length of body (J) 160 microns. Width 
of body (d) 135 microns. Width of girdle about 5 microns. 
One specimen measured. 

Shape . Body shape as in P. depressum . The h/d 
ratio is 0.90. The a/d ratio is 0.28. The b/a ratio is 
0.24. The angle a is 99°. 

Plate pattern. The first apical plate is divided me- 
dially by a suture without intercalary striae; the first 
precingular is divided transversely; the fourth precin- 
gular is divided by a suture in the longitudinal axis; the 
first and second intercalary plates are displaced to the 
left so that 2a touches 2pr and the suture between 2a 
and 3a lies in the longitudinal axis of the body. There 
seems to be a tendency toward formation of a cleavage 
plane, cutting the body into right and left valves as in 
the Dinophysoidae. 

Comparisons . This form, of which only one speci- 
men was recorded, is peculiar only in its tabulation. 

Remarks . The aberrant behavior of the tabulation 
in this form strikingly demonstrates the caution which 
must be applied in using the plate pattern as the funda- 
mental feature of classification. 

Distribution . This form occurred in the surface 
sample at station 2 in the North Atlantic Drift in May 
1928. The hydrographic conditions were as follows: 



24 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



temperature, 20°5 C; salinity, 36.4 o/oo; pH, 8.23; 
phosphate, 58 mg P04/m3. Type locality: Carnegie 
station 2. 



Peridinium claudicanoides n.sp. 
(Figure 29) 



Dimensions. 



Length of body (1) 166 (154-180) mi- 
Diameter (d) 141 (123-150) microns. Width of 
Ten specimens measured. 



crons. 

girdle about 5 microns. 

Shape . Mid-body similar to that of P. depressum . 
The angle a is 94° (79° to 101°). The h/d ratio is 0.75 
(0.53-0.94). The body is compressed along an antero- 
ventral-posterodorsal axis, running at an angle of about 
55° to the plane of the girdle. The epitheca tapers into 
a short truncated apical horn which is flattened lateral- 
ly at the end so that it is from 1.1 to 1.5 times as wide 
in lateral as in ventral view. The horn extends along an 
axis which lies at an angle of about 65° to the axis of 
depression of the body. The hypotheca terminates in two 
stout pointed antapical horns which are more or less 
triangular in outline. The a/d ratio is 0.30 (0.27-0.31). 
The b/a ratio is 0.28 (0.23-0.35). In lateral view the 
axis of the right antapical horn is in line with the axis of 
the apical horn, but in ventral view it is seen to diverge 
to the right. The left antapical horn is shorter than the 
right and diverges from it laterally and ventrally. The 
girdle follows approximately the same course as in P. 
depressum . 

Plate pattern . The tabulation of the epitheca is of 
the second symmetrical, rarely the first asymmetrical, 
pattern. Tabulation of other parts of theca as in P. de- 
pressum . 

Body wall . The external surface of the theca is 
faintly marked with an irregular reticulation which is 
raised at the intersections so that under low magnifica- 
tion the surface appears spinulose. Pores are scattered 
irregularly over the surface, and bear no relation to the 
reticulations. 

The plates are bordered by simple sutures or wide 
intercalary zones. Rabbet joints occur as in P. depres - 
sum . 

Comparisons . This species is close to P. depres - 
sum . The mid-body has about the same form as in that 
species although somewhat more expanded in the girdle 
region, as is expressed by the low angle. It differs fur- 
ther from P. depressum in the shorter and stouter api- 
cal horn, and in the stout cuneate antapicals. Further- 
more, it may usually be distinguished from P. depres - 
sum by its plate pattern, which is the second symmetri- 
cal. The last feature is not quite reliable, however, 
since one specimen was found with the first asymmetri- 
cal pattern, a tabulation occurring frequently in P. de - 
pressum . 

Distribution . P . claudicanoides was found at 9 sta- 
tions: 5 in the Atlantic and 4 in the Pacific (fig. 20). 
There are 13 records of occurrence: 11 rare, 1 occa- 
sional, and 1 common. It was found more often at the 
surface, with 7 records for the surface, 3 for 50 meters, 
and 3 for 100 meters. There are 11 net records and 2 
pump records. The species was found in May in the north 
temperate regions of the Atlantic, and in October and 
November on both sides of the equator in the tropical 
Pacific. 

In the Atlantic this form was found at four stations 
in the North Atlantic West Wind Drift, stations 1, la, 2, 



and 3; and at one station in the Caribbean, station 32. 
In the Pacific it occurred only off the coast of Colombia 
and Ecuador, stations 35, 35a, 35b, and 40. It is thus 
much more restricted in its distribution and occurs in 
the Pacific at quite different places from P. depressum . 

The surface temperatures at the stations where it 
occurred at any depth varied from 15°.5 to 28°.0 C. The 
ranges of hydrographic conditions in situ were as fol- 
lows: temperature, 13°.8 to 27°.0 C; salinity, 30.0 to 
36.4 o/oo; pH, 7.85 to 8.25; phosphate, 15 to 138 mg 
P0 4 /m 3 . 

Peridinium claudicanoides thus appears to be a 
rare, warm-water species possibly with a restricted 
distribution. It will be noted that it occurred in a wide 
range of salinities but never in the barren waters with 
low phosphate content. If this correlation is correct, it 
is an unusual feature for a tropical form. Type locali- 
ty: Carnegie station 2. 



Peridinium oceanicum Vanhoffen 
(Figure 30) 

Peridinium oceanicum Vanhoffen, 1897a, pi. 5, fig. 2. 
Vanhoffen, 1897b, pp. 1-2. Jorgensen, 1905, p. 109. 
Van Breeman, 1905, p. 44. Broch, 1906, pp. 154- 

156. Paulsen, 1907, p. 16, fig. 21. Paulsen, 1908, 
pp. 39, 54. Meunier, 1910, p. 27. Broch, 1910, p. 
190. Schroder, 1911, pp. 17-19, 21, 40. Mangin, 
1913, p. 156. Paulsen, 1913, pp. 279-281, pi. 48. 
Jorgensen, 1913, pp. 5-6. Meunier, 1919, pp. 15-19, 
pi. 15, figs. 7-23, pi. 16, figs. 21-23. Paulsen, 1931, 
p. 66, fig. 37, p. 55. Pavillard, 1931, pp. 56-57, 
111, 125, 127, 129, 131, 133. 

Peridinium divergens . Stein, 1883, pi. 10, fig. 7. 

Peridinium depressum var. oceanica, Ostenfeld, 1900, 
p. 57, tables 2-7. Gran, 1902, p. 192. 

Peridinium divergens var. elegans Cleve, 1900b, p. 260. 
Karsten, 1906, pp. 206, 209, 210, 213, 216,217,243, 
245-247, 249, 257, 258, 260-261, 265-266,268, 272, 
274-277, 279, 285, 287, 289, 293, 295 r 296, 298, 301, 
311-312, 317-318, 328, 330-330,337,352-356, 416, 
447, 450, 540. Karsten, 1907, p. 416. 

Peridinium depressa var. oceanica , Ostenfeld, 1900, tab. 1 

Peridinium elegans var., Karsten, 1905, pp. 34, 132, pi. 
19, figs. 5, 6. 

Peridinium elegans , Karsten, 1905, pp. 179, 208. 

Peridinium depressum oceanicum f. typica Broch, 1906, 
p. 152. 

Peridinium oceanicum f . typica Broch, 1906, pp. 154- 

157, fig. 3. Broch, 1910, pp. 190-191. 
Peridinium divergens oceanicum Karsten, 1907, p. 224, 

227, 228, 230-232, 257, 260-261, 272, 281,290, 416, 

447, 450, 472, 540. 
Peridinium oceanicum var. typica Paulsen, 1908, p. 55, 

fig. 69. Mangin, 1913, p. 222. Lebour, 1925, p. 121. 
Peridinium ozeanicum , Schroder, 1911, pp. 16, 25. 
Peridinium murrayi var. occidentalis Pavillard, 1931, 

pp. 57, 114, 121, 147, 151, 153, 171, 181, 185, 187, 

189, fig. 9B, pi. 2. 
Peridinium murrayi var. orientalis Matzenauer, 1933, 

p. 465, fig. 46b. 

Dimensions . Length of body (I) 246 (225-268) mi- 
crons. Diameter of body (d) 124 (108-137) microns. 
Width of girdle about 5 microns. Thirty-four specimens 
measured. 

Shape . Body shape similar to P. depressum (seep. 
16) but longer and more slender with relatively long 
horns. The h/d ratio is 1.42 (1.27-1.68). The a/dratio 
is 0.58 (0.48-0.74). The b/a ratio is 0.12 (0.07-0.15). 
The angle ais 119° (109-135°). 



FAMILY PERIDINIACEAE 



25 



Plate pattern . The tabulation is of the first sym- 
metrical pattern, rarely of the first asymmetrical. The 
latter was observed in one specimen only. The x-ratio 
varied from + 0.70 to +1.30 in the symmetrical patterns 
and was -1.1 in the specimen with the asymmetrical pat- 
tern. Tabulation in other regions as in P. depressum. 

Body wall . Details of thecal structure the same as 
in P. depressum . In the tropical specimens the body 
walls were thinner and the surface sculpturing less de- 
veloped than in the northern representatives. 

Variation and comparisons . This species is close- 
ly related to P. depressum , from which it may be dis- 
tinguished by its greater h/d ratio (greater than 1.20) 
and by its greater angle <x (greater than 105°). (See p. 
15.) * 

There are a great number of variants of P. oceani- 
cum , which have caused considerable trouble among in- 
vestigators of this group. (See below.) It is not likely 
that this group will be dealt with in an orderly manner 
until the description of the body shape is expressed nu- 
merically, thus allowing frequency studies for the es- 
tablishment of groupings and intergradations. 

From the Carnegie material 82 specimens with h/d 
ratios greater than 1.20, i.e., specimens belonging to P. 
oceanicum and varieties, were selected at random from 
widely scattered oceanic stations in the North Atlantic 
and Pacific, and measured. The frequency of their 
length classes (fig. 31) indicates two distinct groups: 
one with lengths from 140 to 200 microns; the other with 
lengths from 220 to 270 microns. Although the two 
groups are distinct, they are, nevertheless, close togeth- 
er. Since observation of the habitat corroborates this 
grouping, it seems justifiable, for the present at least, 
to consider the body length as a specific feature sepa- 
rating P. oceanicum from its varieties. The group with 
greater length is the main species. 

In P. oceanicum proper the body form shows a cer- 
tain stability, but in the group of smaller forms the var- 
iation is extreme (fig. 33). No secondary grouping of 
these smaller forms could be accomplished. Therefore 
they were lumped into a single group, var. tenellum n. 
var. 

In addition to this variety, which was separated on 
the basis of body length and form, three other variants 
of P. oceanicum were found which were aberrant in oth- 
er features; forma spiniferum n.f. and f. tricornutum 
n.f. were segregated on the basis of accessory horns 
(pp. 24 and 25), and f. bisintercalares n.f. was estab- 
lished on the presence of only two anterior intercalary 
plates (p. 24). 

Historical . Vanhoffen (1897a, pi. 2, fig. 5) figured 
a specimen similar to P. depressum but longer and more 
slender. No reference was made to this figure in the 
text; but in another paper VanhOffen (1897b) gave a list 
of species including the name "P. oceanicum Vanhof- 
fen," which has generally been supposed to refer to this 
figure. No description of the species was given by Van- 
hoffen nor was the plate pattern shown. 

This form has been almost universally accepted as 
a distinct species related to P. depressum (Jorgensen, 
1905; Broch, 1906, 1910; Paulsen, 1907, 1908, 1913; 
Mangin, 1913; Pavillard, 1931). Peters (1928) alone has 
combined it with P. depressum . Our own observations 
also indicate that it should be given specific rating. At 
the same time, it is certainly not so easily distinguish- 
able as was formerly supposed. 

Karsten (1906) confused this species with P. ele - 



gans Cleve, a species related to P. grande Kofoid. Kar- 
sten s records of P. divergens var. elegans , as he states 
later (1907), refer to P. oceanicum VanhOffen. Cleve 
(1900b) also confused these two forms. 

Kofoid (1907a) described a form, P. murrayi , as 
"resembling j 5 . oceanicum " but with "lower epitheca 
with more concave sides, longer horn, and longer and 
more divergent antapical horns." A figure was given, 
and the length given as 250 microns and the width 135 
microns. This form seems to have a certain constancy 
and is probably specifically distinct. It was figured lat- 
er by Pavillard (1931) and Matzenauer (1933). It is, how- 
ever, difficult to distinguish Pavillard' s P. murrayi var. 
occidentalis and Matzenauer's P. murrayi var. orien - 
talis from P. oceanicum Vanhoffen. 

Distribution . This is a widely spread species. It 
has been frequently reported from various parts of the 
Atlantic (see Paulsen, 1908; Lebour, 1925; and Pavil- 
lard, 1931) and from the Mediterranean (Forti, 1922). 
Karsten (1905) reported it from the Antarctic. Karsten 
(1907) and Matzenauer (1933) recorded it in the Indian 
Ocean. The only records for the Pacific are those of 
BOhm (1936) between Hong Kong and Shanghai. 

In the Carnegie collection this species was found at 
9 stations, all in the Atlantic. There are 17 records of 
occurrence: 6 rare, 5 occasional, 5 common, and 1 a- 
bundant. It was found about equally at the three levels, 
with 6 records for the surface, 5 for 50 meters, and 6 
for 100 meters. There are 14 net records and 3 pump 
records. All the records are from July and .August 1928. 

The species was found at all stations between Ice- 
land and Labrador, at two stations in the North Atlantic 
Drift (stations 15 and 16), and at one station in the North 
Equatorial Current, station 21 (fig. 20). It was most a- 
bundant in the area between Iceland and Labrador. The 
fact that it was not found on the run from Washington to 
Plymouth during May might indicate that this particular 
occurrence was seasonal. The complete absence of the 
main species from the Pacific is very remarkable. All 
the Pacific material could definitely be placed in var. 
tenellum because of the shorter length. 

The surface temperatures at thfe stations where P. 
oceanicum occurred at any depth varied from 8°.4 to 
26°.0 C. The ranges of hydrographic conditions in situ 
were as follows: temperature, 4°.0 to 26°. 6; salinity, 
34.7 to 36.8 o/oo; pH 7.90 to 8.32; phosphate, 4 to 78 mg 
P04/m3. 

It is obvious from these observations that this spe- 
cies is not restricted to water masses of particular 
characteristics even though its center of abundance is 
definitely in the colder regions. 



Peridinium oceanicum var. tenellum n.var. 
(Figures 32, 33) 

Dimensions . Length of body ( 1) 179 (150-205) mi- 
crons. Diameter (d) 91 (70-106) microns. Width of gir- 
dle about 7 microns. Twenty- seven specimens meas- 
ured. 

Shape . Similar to main species but less slender. 
The h/d ratio is 1.40 (1.25-1.76). The angle a is 126° 
(110°-142°). The a/d ratio is 0.58 (0.42-0.67). Theb/a 
ratio is 0.12 (0.08-0.16). 

Plate pattern . Epithecal tabulation is of the first 
symmetrical pattern. Other areas of theca also as in 
main species. 



26 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Variation and comparisons . The variants of P.o- 
ceanicum are innumerable. In the Carnegie material 
all of them could be separated from the main species by 
their shorter length (p. 23). These shorter forms, how- 
ever, did not allow further segregation, although they 
did not appear to present a homogeneous group. Hence 
they were all lumped into the single variety treated 
here. There was a great variation in the length, diver- 
gence, and thickness of horns, and in the shape of the 
mid-body. The numerous varieties of the species pre- 
sented by other authors have usually been figured in on- 
ly one position, viz., the resting position. The relation- 
ships of these forms to each other and to var. tenellum 
cannot be determined until statistical studies of body 
shape are made. This, of course, cannot be done until 
standard methods of presentation and measuring have 
been adopted. 

Historical. Mangin (1913) described P. oceanicum 
var. parvulum as a characteristic form at Saint-Vaast- 
la-Hougue. Broch (1910b) described P. oceanicum f. 
arupinensis as the typical form of the Mediterranean. 

The most commonly cited variant of P. oceanicum , 
however, is P. oblongum Aurivillius (1898). The cur- 
rent conception of this form seems to be that it is a 
small neritic variety of P. oceanicum . If, however, we 
are to accept the figures referred to by Aurivillius, we 
must consider this form not only smaller than P. ocean - 
icum . but of a somewhat different shape. Aurivillius 
referred to figures 39 and 40 of Bergh (1882) and fig- 
ures 44,1 to 44,5 of Schiitt (1895). In these specimens 
the sides of the body are much straighter than in P. o- 
ceanicum, and the apical horn is less definite. 

Some recent workers (e.g. Bohm, 1936) are includ- 
ing under var. oblongum forms with very rounded bodies 
and distinct, long apical horns. As stated above, the re- 
lationships of these forms cannot be determined until 
frequency studies have been undertaken. 

Broch (1910) stated that P. oceanicum and P. ob - 
longum have a list only on the right side of the sulcus, 
and that f. arupinensis differs in having lists on each 
side. Our observations of P. oceanicum and its variants 
showed that their morphology agrees with that of anoth- 
er members of the section Oceanica in the presence of a 
list on each side of the sulcus. This list is, however, 
frequently difficult to demonstrate. 

Distribution . This variety is widely distributed. In 
the Carnegie material it was found at 60 stations: 14 in 
the Atlantic and 46 in the Pacific. There are 138 rec- 
ords of occurrence: 85 rare, 48 occasional, 3 common, 
and 1 abundant. It was found oftener in the upper levels, 
with 56 records for the surface, 42 records for 50 me- 
ters, and 39 records for 100 meters. It was found in 
both hemispheres and in all months of the year. 

It occurred in widely scattered areas of the Atlantic 
and Pacific oceans (fig. 20). In the Atlantic it was found 
in the North Atlantic Drift, south of the British Isles, off 
the southeast coast of Iceland, and in the Caribbean Sea. 
In the Pacific it occurred at all stations in the general 
area between Ecuador and thd Tuamotus, at Easter Is- 
land, at three stations south of latitude 36° south, at 11 
stations in the three equatorial currents in the central 
Pacific, at 4 stations off Japan, and at 4 stations off the 
west coast of the United States. 

It was found over a great range of hydrographic 
conditions. The surface temperatures at the stations 
where it occurred at any depth varied from 10°.3 to 



28°6 C. The ranges of hydrographic conditions m situ 
were as follows: temperature, 6°7 to 28°.6 C; salinity, 
32.7 to 36.5 o/oo; pH, 7.71 to 8.39; phosphate, 8 to 220 
mg P0 4 /m 3 . 

This form is apparently of world-wide distribution, 
occurring in a wide range of hydrographic conditions. It 
is noteworthy, however, that it was not found at the Car - 
negie stations where the phosphate content of the water 
was low, that is, less than 8 mg per cubic meter. This 
correlation may be significant in explaining its distri- 
bution, since in the warmer areas the phosphate content 
is often less than 4 mg/m 3 . Type locality: Carnegie 
station 14. 



Peridinium oceanicum forma spiniferum n.f. 
(Figure 34) 

Dimensions. Length of body (I) 225 (209-241) mi- 
crons. Diameter (d) 131 (122-140) microns. Width of 
girdle about 5 microns. Three specimens were measured. 

Shape . The h/d ratio is 123 (1.19-1.29). The angle 
oc is 112° (104°-124°). The a/d ratio is 0.47 (0.43- 
0.52); the b/a ratio is 0.11 (0.09-0.14). The distinctive 
feature of this form is the presence of an accessory 
horn, usually spine-tipped, on the fourth apical plate ei- 
ther in the center of the plate or anteriorly. In the spec- 
imens observed, this feature did not entail any change in 
plate pattern. 

Plate pattern . Of the three specimens recorded, 
two showed the first symmetrical and one the first a- 
symmetrical pattern. In one specimen there was a 
lengthening of the suture between 3a and 4pr with con- 
sequent shortening of the suture between 3pr and 4pr. 

Comparisons . This form has been placed in P. oce - 
anicum because most of the specimens had an h/d ratio 
greater than 1.20. Furthermore, the horns are attenu- 
ated as in that species. The mid-body shows a certain 
similarity to P. depressum in its strong depression, in- 
dicated by the comparatively low angle a. . This is not 
enough, however, to come wholly within the range of P. 
depressum . 

Distribution. This is one of the diverse forms 
which originate on the Grand Banks of Newfoundland, 
where organisms are subjected to violent changes in en- 
vironmental conditions (p. 19). It was found in the 50- 
and 100-meter samples at station 13 on the Grand Banks 
of Newfoundland in August 1928. The ranges of hydro- 
graphic conditions in which it was found were as follows: 
temperature, -1°.64 to -1°10 C; salinity, 33.4 to 33.6 
o/oo; pH 7.87; phosphate, 59 to 63 mg P04/m 3 . Type 
locality: Carnegie station 13. 



Peridinium oceanicum forma bisintercalares n.f. 
(Figure 35) 

Dimensions. Length of body (l) 203 (187-224) mi- 
crons. Diameter of body (d) 105 (91-125) microns. 
Width of girdle approximately 5 microns. Three speci- 
mens were measured. 

Shape . Similar to P. oceanicum . The h/d ratio is 
1.40 (1.38-1.41). The angle a is 128° (121°-135°). The 
b/a ratio is 0.13 (0.13-0.15). 

Plate pattern . The tabulation of the epitheca in the 
specimens examined was of the first symmetrical pat- 






FAMILY PERIDINIACEAE 



27 



tern except that there were two, instead of three, inter- 
calates. In one of the three specimens examined, the 
suture between the two intercalaries was so displaced 
to the right of the median body line that it appeared to be 
the normal suture between 2a and 3a and that the left 
plate represented a fusion of la and 2a. In the other 
specimens, however, as in the two-intercalary form of 
P. depressum , the suture between the two intercalaries 
was medially located and thus indicated a more funda- 
mental change in the organization of the plate pattern. 

Comparisons . This form occupies the same posi- 
tion relative to P. oceanicum that P. depressum f. bis - 
intercalatum does to P. depressum . It is distinguished 
from P. oceanicum only by the presence of two instead 
of three anterior intercalary plates. 

Occurrence. This form appeared at three stations, 
all in the Atlantic: in the North Atlantic West Wind Drift 
(station 2) at the surface, on the Grand Banks of New- 
foundland (station 13) at 50 meters, and in the Caribbean 
Sea (station 31) at 100 meters. Its relative abundance at 
the last station was occasional; at the other two stations, 
rare. The ranges of hydrographic Conditions in which it 
was found were as follows: temperature, -1°.64 to 
22156 C; salinity, 33.4 to 36.5 o/oo; pH, 7.86 to 8.23; 
phosphate, 28 to 58 mg P04/m 3 . 

It is obvious from the above data that the aberrant 
pattern exhibited by forma bisintercalares does not ap- 
pear under any limited set of hydrographic conditions. 
Thus, it is probable that the causes of the development 
of this pattern are genetic rather than environmental. 
Type locality: Carnegie station 13. 



Peridinium oceanicum forma tricornutum n.f. 
(Figure 36) 

Dimensions. Length of body (_1_) 203 microns. Di- 
ameter (d) 120 microns. Width of girdle about 5 microns 
One specimen was measured. 

Shape . The general dimensional relationships are 
similar to those in P. oceanicum . The h/d ratio is 1.21. 
The angle a. is 110°. The a/d ratio is 0.48. The b/a 
ratio is 0.13. The left side of the mid-body is swollen 
into a roughly hemispherical protuburance involving 
both the epitheca and the hypotheca. The proximal end 
of the girdle has an unusual displacement anteriorly, o- 
ver four girdle widths. 

Plate pattern . The epithecal tabulation is of the first 
symmetrical pattern. The x-ratio is +1.43. The hypo- 
thecal side of the hemispherical protuberance is drawn 
out into a hollow horn with attenuated tip. This horn is 
composed of one plate representing an additional or pos- 
terior intercalary plate, inserted between the first, sec- 
ond, and third postcingular and the first antapical plates. 

Comparisons . Whether this form represents a pre- 
mature development of the theca during division, or 
whether it is an expression of a definite tendency in the 
thecal variation, cannot be determined. It is unique in 
that it is the only specimen observed in which any vari- 
ation occurs in the hypotheca. 

Remarks . Names were assigned with hesitancy to 
such aberrant forms as f . tricornutum and f. spiniferum 
because of the realization that these forms may repre- 
sent pathological conditions. Since there were no defi- 
nite indications of the pathological nature of the speci- 
mens examined, however, and since some species of the 
Peridiniales, e.g., Ceratium hirundinella , normally 



have multiple horns, it was decided to assign names to 
these forms, thus expressing the possibility of their 
representing incipient species. 

Distribution . The specimen was collected in Au- 
gust 1928 in the 50-meter sample at station 13 on the 
Grand Banks of Newfoundland, where so many variants 
of P. depressum and P. oceanicum were found. The hy- 
drographic conditions were as follows: temperature, 
-1°64 C; salinity, 33.4 o/oo; pH, 7.86; phosphate, 60 mg 
P04/m3. Type locality: Carnegie station 13. 



Artificial Key to the Units of the Section Oceanica 
Treated in this Report 

A. The h/d ratio less than 1.20; or if greater, the angle 
a. less than 105° B 

A. The h/d ratio more than 1.20 and the angle oc great- 
er than 105° : H 

B. The angle oc 105° or less C 

B. The angle oc greater than 105° F 

C. Epitheca with 2 intercalary plates 

P. depressum f.bisintercalatum n.f. 

C. Epitheca with 3 intercalary plates D 

D. Epitheca composed of 17 major plates 

P. depressum f. multitabulatum n.f. 

D. Epitheca composed of 14 major plates E 

E. Antapical horns cuneate; b/a ratio greater than 0.23; 
epithecal pattern usually second symmetrical . . . 
P. claudicanoides n.sp. 

E. Without this combination of characters 

P. depressum Bailey 

F. The a/d ratio less than 0.30 

P. depressum var. parallelum Broch 

F. The a/d ratio more than 0.30 G 

G. Lateral contours of body convex 

P. depressum var. convexius n.var. 

G. Lateral contours of body straight or slightly convex . 
P. depressum var. rectius n.var. 

H. Epitheca with 2 intercalary plates 

P. oceanicum f. bisintercalares n.f. 

H. Epitheca with 3 intercalary plates I 

I. Fourth apical plate bearing a prominent spine . . . 

P. oceanicum f. spiniferum n.f. 

I. Fourth apical plate not bearing a prominent spine . . 

J 

J. Hypotheca with an intercalary plate bearing a horn . 

P. oceanicum f. tricornutum n.f. 

J. Hypotheca without such a plate K 

K. Total length (1) less than 210 microns 

P. oceanicum var. tenellum n.var. 

K. Total length (1) more than 210 microns 

P. oceanicum VanhOffen 



Peridinium crassipes Kofoid 
(Figure 37) 

Peridinium crassipes Kofoid, 1907a, pp. 309-310, pi. 31, 
figs. 46, 47. Paulsen, 1907, p. 17, fig. 24. Paulsen, 
1908, p. 58, fig. 73. Broch, 1908, p. 5. Broch, 1910b, 
p. 52, fig. 27. Okamura, 1912, p. 18, pi. 4, figs. 63a- 
c. Lindemann, 1924, p. 230, pi. 4, figs. 80-86. Pe- 
ters, 1928, p. 42, figs, lla-h. Matzenauer, 1933, p. 
467, fig. 50. Bohm, 1936, p. 41, fig. 16c. 

Dimensions. Length of body (1) 105(88-120) mi- 
crons. Width of body (d) 111 (90-130) microns. Width 
(g) 80 (65-94) microns. Width of girdle about 6 microns. 



28 



STUDIES m THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERTOINIALES 



Twenty-two specimens were measured. 

Shape . Body short and wide, resembling somewhat 
P. depressum var. parallelum Broch. TheJ/d ratio is 
0.95 (0.80-1.04). The h/d ratio is 0.76 (0.60-0.86). In 
ventral view both the epitheca and the hypotheca rather 
abruptly constricted distally. The angle a is 89° (74°- 
102°). Apical horn 1/4 to 1/3 total length of epitheca; 
base broad. Apex about 1 girdle width in diameter. Ant- 
apical horns terminated by solid spines. Right horn a- 
bout 2 girdle widths longer than the left. There is no 
dorsoventral compression of the body in the girdle re- 
gion, so that in apical view, the body is almost circular 
except for the deep indentation at the sulcus, which is 
about 3 girdle widths deep. The g/d ratio is 0.73 (0.64- 
0.80). There is sometimes a slight development of ven- 
tral limbs in the girdle region (as seen in apical view), 
but this is not very marked. 

The girdle is equatorial, sinistral, displaced about 
2 girdle widths. The ends of the girdles themselves 
are scarcely (about 0.5 girdle width) displaced, however, 
owing to the posterior curvature of the distal end. There 
is no girdle overhang; the girdle ends are separated by 
the anterior end of the ventral area. Girdle slightly con- 
cave. In side view the girdle is seen to be inclined at an 
angle of 75° to the longitudinal axis (the axis running 
from the apex to the antapex of the body). 

The ventral area extends from the anterior edge of 
the girdle posteriorly to the antapex, which is located 
almost centrally (when specimen is seen in antapical 
view). Area subtruncate anteriorly; rounded posterior- 
ly; left side almost straight; right side angular so that 
the greatest width, equaling about 4 girdle widths, oc- 
curs about one-third of distance from girdle to right 
antapical horn. Right side of ventral area on a level 
with, and taking a prominent place in, the ventral aspect 
of main body; but left side of area scarcely evident on 
the main body. Flagellar pore roughly elliptical in out- 
line and about 2.5 girdle widths long, lying in the middle 
of sulcus proper, which occupies left half of ventral a- 
rea. Sulcus rotated on its longitudinal axis in such a way 
that pore faces more to the left than ventrally. Sulcus 
and pore covered by left sulcal list. 

Plate pattern . Epithecal plate pattern typical of di- 
vergens group, with first apical touching precingulars 1, 
2, and 7, and apicals 2 and 4; and with second anterior 
intercalary touching only fourth precingular (fig. 37 A). 
Precingular plates fairly evenly spaced around girdle. 
Precingular 2 has a somewhat smaller girdle margin 
than its fellow, precingular 6, on the right side, but this 
discrepancy is not nearly so pronounced as in the case 
of P. truncatum (p. 28). 

Hypothecal pattern typical of genus (fig. 37C). At 
apex there are 2 platelets in addition to apical plates, as 
in P. depressum . Ventral apical platelet about 1 girdle 
width long. Apical pore platelet a ring structure simi- 
lar to that in P. depressum . 

Girdle consists of four unequal plates (fig. 37D). 
First girdle plate (gl) is a short, squarish plate adjacent 
to the ventral area. The second and fourth (g2, g4) about 
equal in length and occupying the ventral portions on the 
two sides of girdle. Lateral and dorsal sides of girdle 
composed of the long third girdle plate (g3). 

Ventral area composed of six plates (fig. 37E, F). 
Only four of these are visible in undissected specimens, 
the other two hidden as in the case of P. depressum. All 
plates homologous with those in P. depressum , a species 
with a ventral area in many respects similar to that of 



P. crassipes . (See comparisons.) Anterior sulcal plate 
(as) occupies most of the anterior part of the area and 
forms anterior margin of flagellar pore. Left sulcal 
plate (Is) comprises most of the left side of sulcus and 
forms left edge of flagellar pore. Right sulcal p late (rs) 
occupies most of right side of ventral area, is raised 
practically to the level of the main body plates, as in P. 
truncatum (p. 28), and forms right margin of flagellar 
pore and sulcus proper. Posterior sulcal plate (ps) 
forms posterior part of the area and is U-shaped in out- 
line. Its right side is expanded into a squarish process 
which lies posterior to right sulcal plate. Its middle 
portion is very narrow. Its left side is elongated into a 
slender process which borders posterior left edge of the 
sulcus and is raised to the level of the body plates, fit- 
ting in between the first postcingular and first apical 
plates. This portion bears the posterior part of the left 
accessory sulcal list on its inner margin. At the poste- 
rior edge of flagellar pore between the right and the left 
sulcal plates is a small, squarish, trough- shaped plate, 
the posterior accessor y sulcal plate (pas). Along the 
right side of pore, underneath the left edge of the right 
sulcal plate, is a thin plate, the right internal sulcal 
plate (ris), which has a posterior arm turned into the 
body of the specimen. A similar projection into the pro- 
toplast at the anterior edge of the pore is not a separate 
plate but a process on the under side of the anterior sul- 
cal plate. 

Body wall . Body plates and some sulcal plates cov- 
ered with a light reticulation which is usually irregular- 
ly raised at the angles of the meshes. Size of meshes, 
except over rabbeting membranes, from 0.3 to 0.5girdle 
width. Over these membranes, in individuals without in- 
tercalary zones, the meshes are noticeably larger, 0.6 
girdle width or more; but reticulations are much less 
well developed, the thecal wall appearing thinner; and no 
pores occur. In the more finely reticulated areas, there 
are fairly regularly spaced pores, usually one per mesh. 
In these areas the thecal wall is thicker and the meshes 
of the reticulations sometimes give the appearance of 
pits, although their edges are always angular. The gir- 
dle plates do not bear these reticulations, but have ir- 
regular transverse ridges which usually extend only half- 
way from the edge of the girdle, and may be connected, 
forming a sort of reticulation. There are no pores in the 
girdle although the median line of the girdle has a spon- 
gy nature. Intercalary zones are common. 

Lists . Girdle lists about 1 girdle width wide and 
strengthened by small ribs which extend centripetally 
from outer margin halfway to body. These ribs are 
placed from 0.2 to 0.3 girdle width apart. In the apical 
region there is a system of lists similar to that in P. de- 
pressum except that the most distal parts are less well 
developed. The lists running down the body from the a- 
pex are larger than in P. depressum , sometimes being 
as much as 1.5 girdle widths wide. The lateral ones (at- 
tached to ap3) usually visible in ventral and dorsal views. 
The right and left segments of the apical list (ral, lal, 
fig. 37G), which run down the ventral side of the body 
and are attached to the fourth and second apicals, re- 
spectively, are clearly seen when specimen is viewed in 
lateral aspect. 

Lists in the sulcal region well developed. Left sul- 
cal list continuous with posterior girdle list and at- 
tached to po; continuous posteriorly with the left acces - 
sor y sulcal list (la), which is attached to the right edge 
of the left limb of the posterior sulcal plate (ps). The 



FAMILY PERIDDMIACEAE 



29 



left sulcal and the left accessory sulcal lists form the 
functional left sulcal list. They are very broad, about 
1.5 girdle widths wide, except at their point of junction, 
where they are constricted to 0.7 girdle width. Posteri- 
orly, the left accessory sulcal list extends as a free sail 
about 1.5 girdle widths long. These two lists extend 
more or less laterally over the sulcus, covering all its 
left half and the flagellar pore. Right sulcal list very 
small. Posterior sulcal list well developed medially, 
having a width of about 0.7 girdle width, but rapidly di- 
minishes anteriorly as it runs up the sides of the sulcus. 
The right accessor y sulcal list (ras) is thick and nar- 
row, overhangs the flagellar pore on its right side, and 
continues posteriorly to the posterior sulcal plate, form- 
ing a trough with the posterior accessory sulcal plate. 
There is no posterior accessory sulcal list. 

" Spines. " Solid antapical spines end antapical 
horns. They are about 2 girdle widths long; the right 
is slightly longer than the left. Cursory examination of 
intact specimens in ventral view shows a spine posteri- 
orly at each side of sulcus. Spines are simply optical 
effects produced by the greater absorption of light at 
points where line of vision falls on tangents of the cur- 
vature of the posterior sulcal lists. Lists are difficult 
to see because of transparency, except at these spines. 

Comparisons . Peridinium crassipes is distin- 
guished from other species of Metaperidinium by its 
short, broad body and by its short horns. 

It is of particular interest to compare the ventral 
area of P. crassipes with that of P. depressum and that 
of P. truncatum , since crassipes has a structure which 
in some respects is transitional between the latter two 
species. The margins of the ventral area are similar to 
those in P. truncatum . The body sutures have the same 
relation to those of the ventral area as in that species. 
The tabulation of the ventral area is transitional be- 
tween P. depressum and P. truncatum . The largest 
plate of this area, the right sulcal, is raised so that it 
forms part of the body proper, as in P. truncatum . On 
the other hand, the region immediately surrounding the 
flagellar pore agrees well with P. depressum . There 
are internal structures at the anterior and posterior 
ends of the pore. A semilunar structure occurs at the 
right edge of the pore on the internal surface of the right 
sulcal plate. This structure is composed partly of an 
internal plate, the right internal sulcal plate, as in P. 
depressum. The very small posterior accessory sulcal 
plate is probably homologous to the similar plate in P. 
depressum and the larger plate of the same name in P. 
truncatum . 

The sulcal list system is also transitional between 
P. depressum and P. truncatum . The right accessory 
sulcal list ends at the posterior end of the right sulcal 
plate, as in P. depressum ; it does not join with any pos- 
terior accessory list as is the case in P. truncatum . 
The course of the left accessory sulcal list is as in P. 
truncatum . Otherwise the lists of the posterior region 
of the sulcus are quite different from those in that spe- 
cies and are similar to those in P. depressum . There 
is no posterior accessory list connecting the right and 
left accessory lists, and the left accessory list extends 
posteriorly as a free lobe. 

Historical . Kofoid (1907a) described this species 
from the neritic plankton off San Diego, California. 

Paulsen (1908) considered figs. 43, 1-2 of Schutt 
(1895) to represent this species, but in our opinion this 
is uncertain. The side view (fig. 43, 2) might well be P. 



crassipes , but the dorsal view (fig. 43,1) does not show 
sufficient expansion in the girdle region. 

The antarctic form reported by Peters (1928) is 
distinctly different from the northern form, but Peters 
considers the two forms to fall within the limits of a 
single species. The antarctic form has a peculiar an- 
gularity of the body and thickness of antapical horns not 
found in the northern form. 

Jorgensen (1913) separated P. curtipes from P. 
crassipes , on the basis of its yellow, instead of pink, 
color; its greater expansion in the girdle region, and 
the shape of the girdle on the left ventral side. Lebour 
(1925) accepted this species of JOrgensen but Peters 
(1928) rejected it. Peters pointed out that species of 
Peridinium cannot be distinguished by their color, as 
this is variable. He also was of the opinion that the 
shapes of the body and girdle are indistinguishable in P. 
curtipes and P. crassipes . Matzenauer (1933) accepted 
P. curtipes and figured a specimen with even greater 
expansion of the girdle region than that of Jorgensen's 
species, and with short, conical, divergent antapical 
horns. 

Since both these species have been very inadequate- 
ly figured, and especially since very little is known re- 
garding any morphological feature of P. curtipes , it is 
not possible at this time to pass a proper judgment on 
the authenticity of P. curtipes . 

The ventral area of P. crassipes had not been ana- 
lyzed until the present investigations. Kofoid's (1907a) 
figures show that certain parts of the area are promi- 
nent and on a level with the main body plates, but even 
the main features of the area are omitted and the flagel- 
lar pore is erroneously indicated at the anterior end of 
the ventral area. 

Distribution . Peridinium crassipes is probably 
widespread. If we consider Jorgensen s P. curtipes as 
Peters (1928) suggested, we have records of occurrence 
from all parts of the Atlantic (Lebour, 1925). Under the 
name P. crassipes , it was reported from the Antarctic 
by Peters (1928), and from the Indian Ocean by Matzen- 
auer (1933), and from the Mediterranean by Forti (1922) 
and Issel (1928). In the Pacific it was reported from San 
Diego, California, by Kofoid (1907a), and from the east- 
ern Pacific, between Hong Kong and Shanghai, by Bohm 
(1936). 

The Carnegie collection furnishes many new locali- 
ties for this species in the Pacific, viz., 50 widely scat- 
tered stations in the tropical and subtropical regions 
(fig. 38). There are 107 records of occurrence; 63 rare 
and 44 occasional. It was found about equally at the 
three levels, with 30 records for the surface, 39 for 50 
meters, and 38 for 100 meters. There are 14 pump rec- 
ords and 93 net records. The species was found in both 
hemispheres in all months of the year except June, July, 
and August. The records of "occasional" are scattered 
irregularly over its range. 

The Carnegie records of P. crassipes are limited 
entirely to the Pacific. In the eastern Pacific it was not 
found north of Guam, whereas in the western Pacific it 
occurred as far north as latitude 33° north and as far 
south as latitude 40° south. 

The surface temperatures at the stations where the 
species occurred at any depth varied from 15°.0to28°.6 C. 
The ranges of hydrographic conditions in situ were as 
follows: temperature, 10°.8 to 28°.3 C; salinity, 31.6 to 
36.4 o/oo; pH, 7.76 to 8.47; phosphate, 3 to 159 mg 
| P04/m3. 



30 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



The distribution of P. crassipes at the Carnegie 
stations is unexplainable unless we assume that the oc- 
currence is sporadic. The species is eurythermal and 
has been found by other investigators over wide areas of 
the Atlantic, from the tropics to the North Sea, yet it was 
absent from all Carnegie stations in the Atlantic. In the 
Pacific, in the Carnegie collection, it occurred mostly 
in the warmer regions but was not found on the line of 
stations between Guam and San Francisco, which passes 
through both cold- and warm- water regions. It did oc- 
cur, however, in the southeastern Pacific in water of 
low temperature. 



Peridinium truncatum n.sp. 
(Figures 39-41) 

Dimensions . Total length (1) including the apical 
and right antapical horns 230 (196-265) microns. Length 
(h) from tip of apical to posterior end of sulcal 161 (138- 
210) microns. Diameter (d) 159 (130-200) microns. Di- 
ameter (g) 80 (65-105) microns. Width of girdle 5-6 mi- 
crons. Twelve specimens were measured. 

Shape . Body shape characterized by pronounced 
features. Mid-body compressed anteroposteriorly in 
girdle region, especially at the sides, to such a degree 
that the lateral sides are scarcely thicker than the gir- 
dle is wide (fig. 39E). In contrast with this extreme 
compression of the mid-body, all the horns are so long 
that the epitheca as well as the hypotheca is about 1.5 
times longer than the dorsoventral diameter. The 1/d 
ratio is 1.45 (1.27-1.57). The h/d ratio is 1.01 (0.91- 
1.17). The angle a. is 47° (34°-65°). The rapid taper of 
the mid-body into the horns is roughly the same on all 
sides; thus the horns are almost symmetrical and the 
marginal curvatures of the mid-body are similar in ven- 
tral and lateral views. All horns are tubular distally 
and elongated. Distal one-third to one-half of antapical 
horns are of uniform diameter. End of apical horn a- 
bout 1.5 girdle widths wide; ends of antapicals about 1 
girdle width. Antapical horns truncate to slightly round- 
ed, but never pointed. 

In apical view the body is basically reniform but 
with ventrolateral limbs greatly elongated. Since the 
prolongation of these limbs is a fundamental character- 
istic of the species, it is necessary to express it numer- 
ically in order that a proper delimitation of the species 
may be obtained. For this reason, the width of the limb 
(r) was measured as described on page 13 (fig. 8). This 
width is best expressed as a fraction of g. The r/g ratio 
in this species is 0.47 (0.43-0.51). Although this ratio 
is sufficient to characterize the species, it is notewor- 
thy that the length of each limb, measured from the apex 
of the body, is at least 1.25 times the dorsoventral di- 
ameter of the body. Another measurable feature which 
is significant in this connection is the ventral projection 
of these limbs; this projection, beyond the median ven- 
tral point, is usually 0.5 times the dorsoventral diame- 
ter of the body. The g/d ratio is also characteristic, 
being 0.48 (0.41-0.54). 

There is practically no real displacement of the 
girdle, although there is frequently an apparent one if the 
specimen is not seen in an exact ventral view. This ap- 
parent displacement may be dextral or sinistral depend- 
ing on the direction of displacement of the specimen. 
Girdle ends separated by the wide anterior portion of 
the ventral area. In lateral view the girdle is seen to be 



inclined about 15° to the longitudinal axis. It is only 
slightly concave. 

Ventral area occupies a large part of ventral sur- 
face of body. About half the area of the right ventral 
portion of the hypotheca and part of the posterior left 
portion are composed of elements of the ventral area. 
These parts of the ventral area occupy an integral part 
of the body and are set into the general body contours 
without any break. Sulcus proper composed of the cen- 
tral elements of the ventral area (see below). Flagellar 
pore oval, about 3 girdle widths long, and situated some- 
what anterior to center of ventral area. The sulcus is 
so rotated on its longitudinal axis that the pore faces to 
the left rather than ventrally. Pore covered by sulcal 
lists so that it does not face the exterior directly. 

Plate pattern . Pattern of major body plates typical 
of divergens group. At the apex of body, there are 2 
platelets in addition to the apical plates. Ventral apical 
platelet long and narrow, more than 7 girdle widths long, 
lying just anterior to the first apical and between the 
second and fourth (fig. 39C, E). Apical pore platelet is 
a ring platelet, set inside the ends of apicals 2, 3, and 
4, and the ventral apical platelet. 

Epithecal pattern not symmetrical in respect to pre- 
cingular plates. Precingular 2 is much narrower, both 
relatively and actually, than corresponding plate on right 
side, precingular 6. The girdle border of pr2 usually 
less than one-fourth that of pr6 (fig. 39A). To compen- 
sate for this, pr3 has a much longer girdle margin than 
its fellow pr5 on the right side. Precingular 2 narrows 
very markedly toward girdle, so that its width at girdle 
may be as little as one- half its greatest width. 

Girdle composed of four unequal plates (fig. 39G). 
First girdle plate somewhat narrower than long (fig. 
39D). Second and fourth extend on either side of sulcus 
almost to the most ventrolateral points of girdle on each 
side. The rest of the lateral and dorsal parts of girdle 
consist of the extremely long third plate. 

Pattern of hypothecal plates typical of divergens 
group. Sulcal plates take a prominent place in the ven- 
tral aspect of body, a characteristic feature in this spe- 
cies. Right sulcal plate occupies a large part of ventral 
surface of hypotheca. The left limb of the posterior sul- 
cal plate fits into the major body plates between the first 
postcingular and first antapical (fig. 39E) in such a way 
that it might be mistaken for a major body plate in un- 
dissected specimens. 

Ventral area composed of five plates, all external 
(fig. 39D). Anterior sulcal plate occupies most of the 
area between the ends of the girdle and forms anterior 
margin of flagellar pore. It bears a process at its pos- 
terior end which projects into the cell body. Left sulcal 
plate occupies the left central and the posterior central 
regions of the ventral area and, in its anterior half, 
forms the left margin of the flagellar pore. Posterior 
sulcal plate more or less U-shaped, forms posterior 
part of ventral area, is far removed from flagellar pore, 
and is very complex. Its left limb forms a large, four- 
sided area in the hypotheca, extends from antapex half- 
way to girdle, and fits into the hypothecal pattern poste- 
rior to first postcingular. Its right limb lies posterior 
to sulcal plate and is also raised to a position where it 
must be considered part of the hypothecal pattern (fig. 
39E). The right sulcal plate , which is the largest in the 
ventral area, extends from posterior sulcal plate to epi- 
theca, where it has a narrow extension lying against the 
distal end of girdle and against seventh precingular. Ii. 



FAMILY PERIDINIACEAE 



31 



its middle part it forms the right margin of flagellar 
pore. It is definitely raised to a position equivalent to 
that of a hypothecal plate. In its anterior half it has a 
dome- shaped prominence which rises over the flagellar 
pore (fig. 41). At the middle of the left side of this 
plate, at the posterior end of the flagellar pore, there is 
a process which projects into the cell body (fig. 39F). 
Between the posterior half of the left sulcal plate and 
the posterior half of the right sulcal plate there lies a 
narrow plate about 4 girdle widths long, the posterior 
accessor y sulcal plate , the homologue of the very mi- 
nute plate at the posterior end of the flagellar pore in P. 
depressum and P. crassipes . Anteriorly it touches the 
flagellar pore, and posteriorly, where it borders the 
posterior sulcal plate, it is about 3 times wider than at 
the anterior end. There is no detachable semicircular 
plate such as occurs in P. depressum and P. crassipes . 

Body wall . Entire surface of the major body plates 
and of all the sulcal plates, except the left and posterior 
accessory sulcal plates, covered with a very prominent 
coarse and regular reticulation. Plates lacking this are 
entirely smooth. Reticulation so deep on apical and ant- 
apical horns, especially in their distal parts, that it 
gives the impression of "spininess" along the edge of 
the horns. Girdle plates with irregularly spaced trans- 
verse ridges which may extend completely across the 
girdle or only part way from the margin on either side. 
The major body plates, the girdle plates, and the sulcal 
plates are pierced by minute, irregularly scattered 
pores. Arrangement of these pores bears no relation to 
reticulations. Usually one or two pores per mesh; those 
on the girdle plates not arranged in rows. 

Intercalary zones not found in our material, except 
in two specimens. 

Lists. Girdle lists comparatively narrow, usually 
less than 1 girdle width wide; strengthened by fairly 
regularly spaced ribs, usually extending completely from 
body to outer edge, but in some cases extending only 
part way from body or from outer edge. 

The apical list system similar to that in P. depres - 
sum . except for a lesser development generally and for 
the absence of the lateral lists. The lists in this region 
are only 0.25-0.50 girdle width wide. Apical list encir- 
cles apex and is composed of three segments: the dor - 
sal , right , and left . Dorsal segment attached to tip of 
third apical and not joined by any lateral lists as in P. 
depressum , P. crassipes , and P. pallidum . Right and 
left segments are attached to apical and ventral edges of 
second and fourth apical plates and continue down the 
ventral side of the body only as far as the posterior end 
of the ventral apical platelet (at the anterior end of the 
first apical plate). Ventral apical platelet is set deeply 
between these two lists (fig. 39C, E, H). 

Development of sulcal lists in this species is of par- 
ticular interest. Left sulcal list is well developed in re- 
spect to its width, which is from 1.0 to 1.5 girdle widths . 
The list extends laterally over the left anterior part of 
the sulcus, overlapping the anterior end of the right ac- 
cessory list and flagellar pore. It is continuous with the 
posterior girdle list and is attached to the first postcin- 
gular plate. Therefore, it can extend only halfway down 
the side of the ventral area. At this point it joins the 
left accessor y sulcal list , which is just as wide as the 
left list but projects ventrally from the body. It is at- 
tached to the left limb of the posterior sulcal plate, and 
is continued around the posterior region of the sulcus as 
the posterior accessory sulcal list . This list, which is 



attached to the posterior sulcal plate, is narrower than 
the last mentioned list and joins the posterior sulcal 
list at the right posterior corner of the ventral area. 
Posterior sulcal list is a poorly developed list along the 
posterior margin of the ventral area. It is composed of 
two segments: the left segment, which is attached to the 
first antapical plate, and the right segment, which is at- 
tached to the second antapical plate. Right sulcal list is 
absent. In other species it runs along the right edge of 
the right sulcal plate (attached, however, to body plates) 
and defines the right margin of the sulcus proper. In 
this species its absence coincides with the raising of the 
right sulcal plate to the position of a major body plate. 
The functional list to the right of the sulcus proper in 
this species is the right accessor y sulcal list . It is at- 
tached to the left edge of the right sulcal plate. It ex- 
tends laterally over the flagellar pore and the posterior 
part of the sulcus. Posteriorly it connects with the pos- 
terior accessory sulcal list but has a free lobe extend- 
ing posteriorly (fig. 39D, E). The posterior accessory 
list extends along the anterior edge of the middle and 
right parts of the posterior sulcal plate. 

Comparisons . This species is rather closely relat- 
ed to P. elegans Cleve (a species not treated in this re- 
port) but may be distinguished from the latter by its 
greater expansion in the girdle region, much greater de- 
velopment of the ventrolateral body limbs, truncated 
antapical horns, and shape of the second precingular 
plate. The r/g ratio is 0.47, as compared with 0.84 for 
P. elegans . The second precingular plate in P. trunca - 
tum narrows toward the girdle, whereas in P. elegans it 
widens. The girdle margin of this plate in P. truncatum 
is less than one-fourth that of po6; in P. elegans that 
margin is more than half that of po6. Furthermore, P. 
truncatum is a larger species, with an h/d ratio on the 
average greater than that of P. elegans . 

A comparison between the ventral areas of P. trun - 
catum and P. depressum is of interest. Although the 
areas are constructed on the same fundamental plan, 
with all plates homologous, they show many marked dif- 
ferences in pattern, contours, and lists. 

The sulcal plates in P. truncatum show a definite 
tendency to become major body plates. Thus a smaller 
number of plates form the sulcus proper in P. truncatum 
than in P. depressum . In P. depressum the left limb of 
the posterior sulcal plate is quite inconspicuous, where- 
as in P. truncatum it is prominent and fits into the main 
body complex posterior to pol. The right limb of the 
posterior sulcal plate likewise is prominent in undis- 
sected specimens of P. truncatum , whereas in P. de - 
p ressum it is quite obscure. The right sulcal plate in P. 
truncatum is a prominent feature of the ventral aspect 
of the hypotheca, whereas in P. depressum it is a com- 
paratively obscure plate of the sulcus. In P. depressum 
it has a trough running the length of it, whereas in P. 
truncatum this plate is convex and actually humped in 
the anterior half. In the sulcus of P. depressum there 
is a right internal sulcal plate; in P. truncatum this is 
absent. The posterior accessory sulcal plate is minute 
in P. depressum , but in P. truncatum it is 4 girdle 
widths long. 

The positions of the sulcal plates in relation to the 
plates of the body differ considerably in the two species. 
In P. truncatum the suture between po5 and ant2 reaches 
the ventral area in the middle of the right sulcal plate, 
whereas in P. depressum this suture runs much more 
posteriorly and reaches the ventral area in the middle 



32 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



of the right arm of the posterior sulcal plate. The su- 
ture between pol and antl, although not exactly compar- 
able in the two species, shows a fundamental difference 
in its course. In P. depressum it reaches the sulcus 
far posteriorly, whereas in P. truncatum it reaches the 
sulcus about midway of its length, about at the midpoint 
of the left sulcal plate. In P. truncatum the left limb of 
the posterior plate extends anteriorly to meet this su- 
ture. All together these differences in sulcal plate pat- 
tern are greater than the differences between the typi- 
cal epithecal patterns of the ortho and meta groups of 
the genus. 

The sulcal list systems of P. truncatum and P. de - 
pressum are as fundamentally different as are the plate 
patterns. In P. depressum the functional border list of 
the right side of the ventral area is the right sulcal list 
(rl, fig. 17), which is attached to the body plates along 
the right edge of the ventral area. In P. truncatum this 
list is practically undeveloped and the functional right 
border list is the right accessory sulcal list (ras, fig. 
39), which in P. depressum is located deep within the 
sulcus proper. There is a similar difference between 
these two species as regards the left side of the sulcus. 
The posterior girdle list and the anterior part of the 
left sulcal list are continuous in both species, but the 
posterior part of the left sulcal list has quite different 
positions in the two species. In P. depressum this part 
is located at the left margin of the deep sulcus and is 
continuous with the anterior part of the left sulcal list 
and with the posterior sulcal list, which, in turn, runs 
around to meet the right sulcal list. Thus, the ventral 
area is bordered by three lists: the primary left, the 
posterior, and the right sulcal lists. In P. truncatum , 
concomitant with the expansion of the ventral area, 
these bordering lists have been subordinated or lost 
completely and there has been a development of acces- 
sory lists bordering the sulcus proper, which occupies 
only a limited part of the ventral area. The anterior 
part of the left sulcal list connects with the left acces- 
sory sulcal list (la), which is joined to the posterior ac- 
cessory sulcal list (pal); this, in turn, is joined to the 
right accessory sulcal list (ras). 

The ventral area of P. truncatum is not so different 
from that of P. crassipes as it is from that of P. depres- 
sum. For a comparison of these features in P. trunca - 
tum and P. crassipes , see "Comparisons" under P. 
crassipes . 

The very marked differences in the structure of the 
ventral areas which were found in these species, as ex- 
emplified by the comparison of P. depressum and P. 
truncatum , are of the greatest importance to the taxon- 
omy of the genus. It is probable that the future classi - 
fication of the species of Peridinium will be based on 
the morpholog y of the ventral area . 

Historical . The figures of Okamura (1912, pi. 4, fig. 
58a-c) given under P. fatulipes probably refer to this 
species. Otherwise, it apparently has not been reported 
before. 

Distribution . Peridinium truncatum was found at 
24 stations, all in the Pacific. There are 46 records of 
occurrence: 27 rare, 16 occasional, and 3 common. It 
was found less at 100 meters than at the other levels, 
with 16 records for the surface, 20 for 50 meters, and 
10 for 100 meters. There were 41 net records and 5 
pump records. 

The species was not found south of 16° south nor 
north of 34° north. There was no definite center of a- 



bundance. The records of "occasional" were scat- 
tered throughout the range. One of the records of 
"common" was near Panama (station 35a), the other 
two were northeast of Samoa (station 157). 

The surface temperatures at the stations where the 
species occurred at any depth varied from 18°. 7 to 
29 °4 C. The ranges of hydrographic conditions in situ 
were as follows: temperature, 14°4 to 29°.2 C; salinity, 
29.7 to 35.9 o/oo; pH, 7.82 to 8.39; phosphate, 4 to 189 
mg P04/m 3 . 

This is apparently a strictly tropical species, per- 
haps confined to the Pacific. Waters of low nutrient 
content are apparently no barrier to it, as there were 5 
records in water containing less than 10 mg P04/m3. 
Type locality: Carnegie station 35. 



Peridinium truncatum forma acutum n.f. 
(Figures 40C, D) 

Dimensions . Length of body ( 1 ) 238 microns. 
Length (h) 168 microns. Diameter (d) 168 microns. Di- 
ameter (g) 98 microns. Width of girdle 6 microns. One 
specimen measured. 

Shape . Body shape close to average for species in 
all respects except in the length of antapical horns and 
the g/d ratio. The J/d ratio is 1.42. The h/d ratio is 
1.00. The g/d ratio is 0.58. The r/g ratio is 0.46. The 
angle oc is 63°. Antapical horns more slender, with 
pointed ends, the right more so than the left. The spec- 
imen observed had broad intercalary zones, so that 
there was a wider spread of the antapical horns than 
otherwise would have been the case. Dorsoventral di- 
ameter greater than in the main species. The angle oc 
is near the maximum for the species. In all other re- 
spects the shape fits description of main species. Plate 
pattern apparently similar in all details. 

Distribution . This form was found only at station 
104, in the western Pacific northwest of the Marshall 
Islands, in May. It was collected in the 100-meter tow. 
The hydrographic conditions in situ were: temperature. 
25°.3 C; salinity, 35.3 o/oo; pH, 8.21; phosphate, 7 mg 
P04/m3. Type locality: Carnegie station 104. 



Peridinium pallidum Ostenfeld 
(Figures 42, 43) 

Peridinium pallidum Ostenfeld, 1899, p. 60. Ostenfeld. 
1900, p. 58. Ostenfeld, (1903) p. 581, figs. 130, 131. 
Cleve, 1900a, p. 17, pi. 7, figs. 21, 22. Jorgensen, 
1905, p. 110. Paulsen, 1907, p. 14. Paulsen, 1908, 
pp. 48-49, fig. 60. Broch, 1910b, p. 45, fig. 17. 
Meunier, 1919, pi. 15, figs. 24-29. Lebour, 1925, 
p. 134, pi. 28, fig. la-d. Peters, 1928, pp. 31-33, 
fig. 7a-c. 

Peridinium pellucidum Gran, 1902, p. 186. 

not Peridinium divergens pallidum Karsten 1906, pi. 23, 
fig. 13a, b. 

Dimensions . Length of body, including right antap- 
ical spine, (I) 94 (44-128) microns. Length (h) 78 (38- 
107) microns. Transdiameter (d) 73 (35-98) microns. 
Diameter (g) 45.9 (33-56) microns. Angle oc 121°.5 
(105°-148°). Width of girdle 5 (3-6) microns. Eighteen 
specimens were measured. 

Shape . Body in ventral view roughly squarish in 
outline, somewhat longer than broad. The h/d ratio is 



FAMILY PERIDENIACEAE 



33 



1.07 (0.95-1.28). Epitheca almost triangular, with apex 
more or less prolonged into apical horn, which may be 
almost absent or as much as 2 girdle widths long. Hy- 
potheca shorter than epitheca. Thus, the girdle is some- 
what posterior. Hypotheca subtruncate with indentation 
at sulcus. The two antapical processes thus formed can 
scarcely be termed horns. Body well rounded in girdle 
region. In apical or antapical view ovate, compressed 
dorsoventrally. The g/d ratio is 0.68 (0.53-0.90). In 
side view body also subovate. Girdle dextral, displaced 
0.5 to 1.0 girdle width, not excavated, inclined (in side 
view) at an angle of about 25°. No girdle overhang. 
Ventral area angular in outline, extending from anterior 
margin of girdle to antapex, and deeply embedded in 
body. Sulcus lies to the left, overhung by the major body 
plates. Flagellar pore oval in outline, centrally located 
in ventral area and covered by the right accessory and 
left sulcal lists (fig. 43B, C). 

Plate pattern . Epithecal tabulation para, hexa. A- 
pex has a ring platelet and a ventral apical platelet (fig. 
43A, D). Four girdle plates. The first girdle plate is 
wider than long and extends somewhat into sulcus (fig. 
42H). Second girdle plate short and squarish. The third 
girdle plate comprises most of the girdle and encircles 
the body almost to ventral area on right side (fig. 42F). 
Fourth girdle plate short and rectangular, about twice 
as long as wide, located at distal end of girdle. 

Ventral area composed of six plates: anterior, left, 
posterior, posterior accessory, right, and right acces- 
sory (fig. 42H). Anterior sulcal plate (as) long, extend- 
ing from apical plate to anterior edge of flagellar pore. 
At the pore it has an internal spongy structure com- 
posed of prongs or forks which fit into similar struc- 
tures on the left and right sulcal plates making an inter- 
locked joint. Left sulcal plate (Is) forms left edge of 
flagellar pore and its anterior end touches first girdle 
plate. It has a thickened ridge along its right edge which 
forms left edge of pore. Posterior sulcal plate (ps) 
forms posterior part of ventral area and is almost U- 
shaped. Its left arm very narrow and carries posterior 
segment of left sulcal list. Its right arm lies posterior 
to right sulcal plate (rs). The latter plate occupies 
most of right side of ventral area and posterior half of 
its left edge forms the right edge of flagellar pore. It 
bears the thick right accessory sulcal list, which pro- 
jects over the pore, as well as internal processes sim- 
ilar to those in P. depressum . There is, however, no 
detachable internal plate. Between the right and the 
posterior sulcal plates, at the posterior edge of pore, 
there is a very small irregular plate, the posterior ac - 
cessor y sulcal plate . It is not more than two to three 
microns long and thus of almost indeterminable shape. 
Anterior to the right plate and opposite distal end of gir- 
dle, there is a short rectangular plate, the right acces - 
sor y sulcal plate . This plate has been found only in P. 
pallidum , which was the only one investigated with a 
right-handed girdle. It is possible that the presence of 
this plate goes with the right-handed girdle, for in such 
a displaced girdle either the right sulcal plate must be 
longer or else there must be an additional plate to oc- 
cupy the increased distance on the right side of the sul- 
cus between the distal girdle end and the antapex. 

Body wall . Surface of body plates covered with ir- 
regular short ridges and tubercles. Pores scattered 
over the major plates and the right, left, and posterior 
sulcal plates. Very irregular row of extremely small 
pores in mid- line of girdle plates. Very small trans- 



verse ridges may extend from outer margins of girdle 
plates toward middle. Intercalary zones common and 
may be quite wide. Intercalary striae run across these. 
Rabbeting membranes well developed and may be as 
much as 2 girdle widths wide. 

Lists . Girdle lists well developed, usually about 1 
girdle width wide. Apical lists well developed, some- 
times more than 1 girdle width wide, similar to those in 
P. depressum but wider and more extensive (fig. 43 A, 
D). Apical list encircles apex; composed of 3 segments: 
dorsal, right, and left. Right and left segments (r.a.L, 
l.a.l.) are attached to apical and ventral edges of second 
and fourth apical plates and continue down ventral side 
of body sometimes as far as girdle. In this case the 
proximal segments of these lists are attached to second 
and sixth precingular plates. Dorsal segment of the ap- 
ical list (d.l.) attached to third apical plate and continu- 
ous with lateral lists. Right lateral list (r.1.1.) and left 
lateral list (1.1.1.) run down sides of body, frequently to 
girdle, in which case their intermediate segments are 
attached to first and third intercalary plates and the 
proximal, or girdle, segments are attached to third and 
fifth precingular plates (fig. 42B). 

Sulcal lists are also well developed. Left sulcal list 
extends laterally over sulcus, about 1 girdle width wide. 
Its anterior segment attached to first postcingular and 
continuous with posterior girdle list. Its posterior seg- 
ment attached to left arm of posterior sulcal plate. Left 
sulcal list terminates posteriorly in mid-region of this 
plate (fig. 42H). Posterior sulcal list , which is attached 
to sulcal margins of antapical plates, and the right sul - 
cal list , which is attached to the second antapical and 
fifth postcingular plates, are poorly developed except 
where they converge and run up the right antapical spine. 
(Fig. 42H). When intercalary striae occur alongthe right 
border of the ventral area there is a weak development 
of the right sulcal list on each edge of the zone. Right 
accessor y sulcal list , which is attached to the right sul- 
cal plate, is well developed and overhangs flagellar pore. 

Other body lists may develop to a minor degree a- 
long the sutures of the major body plates. 

Spines . The two rounded processes of the antapex 
are terminated by spines; the right usually longer than 
the left. Length of right spine is 12.4 (7-17) microns. 
Each spine composed of united short body lists. On the 
right spine, one of these lists is continuous with left 
sulcal list and one with posterior sulcal list. There are 
at least two others which run out of the second antapical 
plate with no relation to sutures. The left spine has four 
or more short lists which bear no relation to sutures. 
One of these articulates transversely with, and runs out 
of, the left sulcal list. It can be disarticulated from it. 
(Fig. 42H). 

Variations . This species varies considerably in 
size and shape. The length varies by three times (44- 
128 microns). The compression of the body is rather 
uniform in most specimens (g/d ratio is about 0.68) but 
some specimens were found with more circular girdle 
section, with g/d ratio as high as 0.90 (g/d ratio of cir- 
cle, of course, 1.00). Width of girdle is remarkably 
constant in its absolute values, about 5 microns. This 
is particularly noticeable in small specimens, where the 
girdle is, then, relatively wide. The plate pattern in this 
species seems to be in a fairly stable state. Only one 
aberration was found. In this the fourth and fifth pre- 
cingular plates were fused. The length of the antapical 
spines varies in accordance with the variation in devel- 



34 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



opment of the lists of the body. The right spine varies 
in length from 7 to 17 microns. 

Comparisons . This is the only species of the para 
group included in this report. It is of particular inter- 
est to compare the ventral area of this species with that 
of species of other parts of the genus. Previous inves- 
tigators have considered Paraperidinium more closely 
related to Metaperidinium than to Orthoperidinium. An 
examination of the ventral areas of the representatives 
presented in this report, however, indicates that Para - 
peridinium is more closely related to the ortho group 
than to the meta. Although the ventral area of P. palli - 
dum is distinctive, it resembles in general that of P. 
depressum more than that of P. crassipes or that of P. 
truncatum . The entire ventral area is depressed in P. 
pallidum , so that it does not take part in the major body 
plate complex. In this respect P. pallidum resembles P. 
depressum . Similarly, the ventral area is bordered by 
the primary sulcal lists rather than by the accessory 
ones, even though the right sulcal list may be double in 
specimens with intercalary zones. The ventral area of 
P. pallidum differs from that of P. depressum signifi- 
cantly only in the absence of the right internal sulcal 
plate and in the presence of the right accessory sulcal 
plate. Its only resemblance to that of P. crassipes and 
to that of P. truncatum is in the relative position of the 
sutures between the first and fifth postcingulars and the 
antapical plates. These sutures join the ventral area a- 
bout halfway between the antapex and the girdle, instead 
of near the posterior end of the area as in P . depressum . 

The absence of antapical horns does not seem to al- 
ter the structure of the ventral area in any fundamental 
way. 

Of the species so far analyzed, this is the only one 
in which the sutures between the girdle plates are so 
near the ventral area, that is, in which the second and 
fourth girdle plates are so short. In other species these 
sutures are in line with the sutures of the major body 
plates. 

Historical . This species is very closely related to 
P. pellucidum (Bergh) Schutt and, in fact, may include 
that species. If so, the name pellucidum has priority 
(Bergh, 1881). In her comparison of these two species, 
Lebour (1925) gives size and shape differences: P. pel- 
lucidum , length 40-68 microns (without spine?), breadth 
36-70 microns; P. pallidum , length 70-96 microns, 
breadth not stated. In the Carnegie material the h val- 
ues vary from 38 to 107 microns with no grouping of 
the values that would suggest the presence of two spe- 
cies or varieties. The diameters vary, similarly, from 
35 to 98 microns. Only eighteen specimens were meas- 
ured, however, and it is possible that additional materi- 
al would indicate the possibility and desirability of sep- 
aration. Lebour (1925) states that the compression is 
very slight in P. pellucidum and gives a figure with cir- 
cular girdle section (pi. 28, figs. 2c, 2d). In the Carne - 
gie material the g/d ratio was found as high as 0.90, 
and this was not correlated with small size but, on the 
contrary, was found in one of the largest specimens of 
the collection. Lebour gives the theca as finely reticu- 
late for P. pellucidum but gives no figures. Peridinium 
pellucidum is supposed to be a neritic form (Lebour, 
1925) and thus would not be expected to be found in the 
Carnegie material. 

In our opinion the existence of two separate forms 
must be held in doubt until a further study is made of the 
small neritic forms. If they are distinct from the form 



found in the Carnegie material, tnen other characters 
than size and shape must be found to distinguish them. 

Distribution . Common in the northern North Atlan- 
tic (Paulsen, 1908; Lebour, 1925). Reported from the 
Mediterranean by Forti (1922). Rare in the Antarctic 
(Peters, 1928). Not reported from the Indian Ocean by 
Matzenauer (1933) nor from the Pacific by Bohm (1936). 

In the Carnegie collection this species was found at 
28 stations; 16 in the Atlantic and 12 in the Pacific. 
There are 57 records of occurrence: 27 rare, 28 occa- 
sional, and 2 common. It was found about equally at the 
three levels although somewhat more frequently in the 
upper levels, with 22 records for the surface, 20 for 50 
meters, and 15 for 100 meters. There are 44 net rec- 
ords and 13 pump records. It was found mostly in the 
northern hemisphere, with only 1 station in the southern, 
and from May to September. 

In the Atlantic it occurred at most of the northern 
stations and as far south as 34° north (station 17). In 
the Pacific it was found at three series of stations: off 
Japan (stations 113-114, 116-117); between San Francis- 
co and Honolulu (stations 133-137); and in the western 
series crossing the equatorial currents (stations 97-98, 
101-102). There was no center of abundance; the rec- 
ords of "occasional" were scattered over its range. 

The surface temperatures at the stations where this 
species was found at any depth varied from 8°. 4 to 28 C .3C. 
The ranges of hydrographic conditions in situ were as 
follows: temperature, -1°6 to 28°.3 C; salinity, 33.4 to 
36.6 o/oo; pH, 7.87 to 8.47; phosphate, 3 to 99 mg 
P04/m 3 . 

Peridinium p allidum is probably a widespread spe- 
cies of sporadic occurrence. It can endure a wide range 
of hydrographic conditions, and factors limiting its pro- 
duction are not indicated in the present data. It can de- 
velop in low concentrations of nutrients, as is shown by 
19 records in water with less than 10 mg P04/m 3 . 



Family CERATOCORYACEAE Lindemann 

Diagnosis . Shape angular to rounded, no prominent 
horns. Epitheca rounded, hornless, spineless, usually 
low. Hypotheca angular to rounded, usually bearing 
prominent spines. Girdle anterior to equator, sinistral, 
not concave, without overhang. Ventral area narrow, 
depressed anteriorly; flagellar pore at anterior end. 
Girdle and sulcal lists well developed. Ventral epithe- 
cal pore present on a2. Plate formula: apical closing 
platelet, 2ap, 2a, 5pr, 6g, 5-6po, lp, lant, 5-6s. Marine. 

Only one genus, which includes seven species. 



Genus CERATOCORYS Stein 
Diagnosis 
See family diagnosis (monogeneric) 

Description 
Size . Length of body (I) varies from 38 microns in 
C. gourretii to 99 microns in C. armata. Width at gir- 
dle in ventral view (d) from 28 microns to 114 microns 
in the same species, respectively. 

Shape . Body angular in all species except C. gour - 
retii , C. horrida being the most angular. At girdle, body 
is squarish to circular or subovate. Girdle placed al- 
most equatorially in C. armata and C. reticulata , in all 



FAMILY CERATOCORYACEAE 



35 



otner species more anteriorly, reaching the most ante- 
rior position in C. gourretii and C. horrida . The e/l 
ratio varies from 0.16 in C. gourretti to 0.46 iiiC. re - 
ticulata . Girdle displaced from 0.5 to 2.5 girdle widths; 
its ends separated by anterior end of ventral area. 

Angularity of body pronounced in lateral view, ex- 
cept in C. gourretii . which is circular to ovate. In other 
species epitheca triangular or triangular with truncated 
apex. Hypotheca, in lateral view, squarish to triangular, 
but always with an oblique shearing posteroventrally 
(except in C. gourretii ) which displaces the posterior 
end of the sulcus some distance from antapex, some- 
times as much as half the distance to the girdle. In C. 
bipes the shape characteristic of the genus somewhat 
obscured by presence of two posterior lobes, one ven- 
tral and one dorsal. 

Greatest width of body is at girdle in all species ex- 
except C. gourretii and C. horrida . In the former spe- 
cies, this occurs about midway between girdle and ant- 
apex, and in the latter species, just posterior to girdle. 

In ventral view, also, body is quite angular in most 
species. Epitheca dome-shaped to triangular in all spe- 
cies, but may be very low in C. g ourretii and C. horrida. 
Hypotheca triangular to squarish. Degree of "squarish- 
ness" expressed by the angle /3. This angle was not 
measured in C. horrida and C. gourretii , as their later- 
al edges are not straight, making accurate measure- 
ments impossible. Fortunately, determination of this 
angle is not necessary for the differentiation of these 
species. Ceratocorys horrida is the most squarish of 
the genus, and its antapex is the broadest; C. g ourretii 
is rounded antapically. In other members the most tri- 
angular is C. reticulata , with an average angle /3 of 37°. 
The other species vary between this value and 15°.5, 
which is found in C. skogsbergii . 

Plate pattern. For plate formula, see family diag- 
nosis (p. 32). Number of plates, twenty-nine, constant. 
Apical pore covered by a closing apical platelet, as in 
Gonyaulax ; a platelet not attached to any body plate. 

There are four plates in apical region, but only two 
of these may be considered apical plates, as the other 
two do not touch the apical closing platelet (fig. 47C). 
First apical squarish and surrounds left and dorsal edg- 
es of platelet; second apical is an elongated ventral plate 
and surrounds right and ventral edges of apex. First 
anterior intercalary squarish and lies to the right of a- 
pex between apicals 1 and 2. Second anterior intercala- 
ry, like second apical, very narrow and lies along left 
edge of second apical although it does not touch apex; 
bears ventral epithecal pore. 

The first three precingular plates occupy the first 
three quadrants of the epitheca, and the fourth and fifth 
occupy the fourth quadrant (fig. 44B). Fifth precingular 
is smaller than the rest and lies posterior to second an- 
terior intercalary and second apical plates. 

There are six girdle plates of approximately equal 
length. 

There are five or six postcingulars; when five, 
there is an extra plate in the sulcus, the homologue of 
the first postcingular. For this reason the numbering of 
the plates is kept uniform in all species, so that in the 
species with only five apparent postcingulars (C. gour - 
retii and C. skogsbergii ) the extra sulcal plate is des- 
ignated postcingular 1. Postcingulars 1 and 2 are small 
and always separated from 3 by a prominent list. Post- 
cingulars 3 to 6 are large and comprise, along with the 
antapical plate, the main body of the hypotheca. Poste- 



rior intercalary lies to the left of sulcus between post- 
cingulars 1 and 2, and antapical plate. 

The single antapical plate occupies most of the ant- 
apex but is displaced to the right so that the left edge of 
antapex is formed by the turned-under edges of the third 
and fourth postcingulars, which are much longer than 
the postcingulars of the opposite side (fig. 47A, B). 

Ventral area composed of five or six plates (figs. 
44A, 58A): an anterior, a posterior, a left, a right, a 
right accessory, and sometimes a left accessory which 
is homologous with the first postcingular in other spe- 
cies. When the flagellar pore is long, it may border the 
right sulcal plate for half its length (C . horrida , fig. 47B), 
but usually the left plate extends so far anteriorly that 
the pore is quite remote from the right plate (C. aultii, 
fig. 56A). 

The plate pattern in Ceratocorys is remarkably con- 
stant. In the main body plates practically no variations 
were found. This is in striking contrast to the condition 
in the genus Peridinium , where there are interspecific 
differences as well as variations within the species. In 
the ventral area of Ceratocorys there are variations to 
be described below, but the number of plates is constant. 

Body wall . Surface smooth to rugose and pitted in 
all species except C. reticulata , which has a heavy retic- 
ulation. Girdle with two rows of pores. Pores also oc- 
cur in sulcal plates and in main body plates. In C. retic - 
ulata pores not demonstrated, but probably present. 

Flagellar pore approximately on a level with distal 
end of girdle. Apical "pore" covered by a platelet as in 
Gonyaulax . Ventral epithecal pore about midway be- 
tween apex and girdle on right edge of second anterior 
intercalary plate near its posterior end. This also re- 
calls Gonyaulax . 

Lists . Girdle lists attain their greatest width in C. 
horrida . Usually with short, strengthening ribs running 
radially. In addition to these ribs other heavy riblike 
structures may be seen when the specimen is viewed in 
apical or antapical aspect. These are not girdle list 
ribs, but transverse girdle lists seen on end (figs. 49E, 
54C). They are attached to the girdle, are spaced at 
fairly regular intervals, and may attain a width exceed- 
ing 1 girdle width and divide the girdle into a series of 
chambers. 

Lists may be developed at the borders of all plates 
and, in addition, on the surface of the antapical plate. 
Lists of C. horrida particularly wide and prominent. 
Two lists are especially important: a list extending ven 
trally from right edge of po3, the ventral bod y list ; and 
one extending dorsally from dorsal edge of po4, the dor - 
sal bod y list . In C. horrida and C . gourretii these bear 
prominent spines. 

In addition to these two lists and to the posterior 
cingular list, there are, on the hypotheca, four nonspin- 
ulate lists. The right sulcal list runs along left edge of 
po6 and is continuous with distal end of posterior girdle 
list. The left sulcal list is attached along right edge of 
pol or po2 and of posterior intercalary plate, joining 
posterior cingular list anteriorly and, sometimes, con- 
tinuous with list of ventral antapical spine posteriorly. 
The right lateral and left lateral lists run from posteri- 
or cingular list down lateral sides of body a short dis- 
tance; the former list at ventral edge of po5, the latter 
at ventral edge of po4. These two lists may be absent. 

Lists of the epitheca more variable than those of 
other parts of body. In general there is a list for each 
suture, although in old specimens the list may not be im- 



36 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



mediately adjacent to the suture. 

Spines . Prominent hypothecal spines are a charac- 
teristic of the genus. All species bear them on the antapi- 
cal plate, and two species, C. horrida and C . gourretii, 
have, in addition, a dorsal and a ventral spine. Dorsal spine 
produced in dorsal body list and ventral spine in ventral 
body list. Antapical plate normally bears two spines in 
C. Pipes , three in C. skogsbergii and C. gourretii , and 
four in C. horrida , C_. armata , C. reticulata , and C. aul - 
tii. When four spines are present, they occur at the four 
edges of the antapical plate. When three are present, it 
is the spine of the right corner that is absent; when two, 
the spines of the right and left corners are absent. 
Smaller spines, representing thickenings in various 
body lists, may occur. There are "brushes" in the long 
spines of C. horrida and C. gourretii ; in the other spe- 
cies spines smaller and usually simple. 

The spines of Ceratocorys are formed on the plan 
of the junction of four lists and are not hollow as has 
frequently been reported in the past. Each spine, when 
viewed on end, presents the form of a cross (fig. 491, K). 
This effect is more pronounced at the base of the spine, 
where the lists are wider, but is evident to a certain ex- 
tent even at the tip. On the antapical spines the lists are 
frequently quite short, not running onto the body to any 
extent (figs. 47, 58); but in other cases they may extend 
to adjacent spines to join with their lists (figs.49G, 59D). 
Lists of dorsal and ventral spines (C. horrida and C. 
gourretii ) are more extensive. The anterior member of 
each runs up to, and joins with, the posterior girdle 
list. The "brushlike" or "featherlike" effect present- 
ed by the distal half of these spines is due to the forma- 
tion of side ribs or riblets from the center of the spine 
along each of the four lists. This structure gives a very 
dense appearance to outer parts of spines. There is, in 
addition, a thickening where the four lists converge, 
forming a sort of solid shaft, and a similar thickening at 
the base of the spines where these join the body. This 
thickening is especially pronounced distally, usually 
forming a club-shaped mass on which the riblets are 
superimposed. 

The four elements of these spines cannot be sepa- 
rated; each is an integral part of the whole. The spines 
do, however, occasionally break off. Specimens have 
been found with stubs of spines and with only the thick- 
ening at the base remaining (figs. 49H, 59D). Spines 
have been observed in the process of breaking off. In 
such cases no separation of the four lists could be ob- 
served; there was a shear transverse cleavage. Wheth- 
er this is autotomy representing an adjustment to a 
change in external environment, as Kofoid (1908) has 
suggested in the case of Ceratium . is impossible to say. 

Although these spines occur approximately along 
sutures, they do not in any case run at the very edge of 
a plate. There is always a zone between the base of the 
spine and the actual suture. This is true of most of the 
nonspinulate lists of the body as well, except in very re- 
cently divided individuals. In such individuals, however, 
the spines on the new moiety have not yet developed. 

Reproduction 

Binary fission is the only type of reproduction defi- 
nitely known in the genus (see p. 36). Daughter cells 
with one moiety undeveloped were found in C. horrida , 
C. armata . and C. gourretii . The line of fission is ir- 
regularly oblique, to the right of the longitudinal axis in 



the epitheca and to the left of it in the hypotheca. To the 
right moiety on the epitheca go precingulars 3, 4, and 5. 
The fission line runs to the left of the flagellar pore, so 
that the right moiety gets all the sulcal plates except the 
anterior. It receives also postcingulars 5 and 6 and the 
antapical plate (figs. 48, 53C). 

Methods of Study 

As an aid to defining the species of this genus, cer- 
tain body dimensions were utilized. These are illustra- 
ted in figure 45. All measurements of the body were 
made with the specimen presenting the full ventral view. 
The length of body (V) was measured from the apex of 
the body, excluding the lists, to the most posterior part 
of the body, excluding the spines and lists, which, in this 
view, is near the dorsal part of the specimen. The di- 
ameter of the body at the girdle (d) is self-evident. The 
relative length is expressed by thej/d ratio. The height 
of the epitheca (e) was measured from the apex of the 
body to the proximal end of the girdle at its anterior 
edge. This dimension is always expressed as a fraction 
of the body length (e/l_ ratio). The angle /6 is the angle 
which the left contour of the body makes with the longi- 
tudinal body axis, A-B. This angle gives a measure of 
the amount of narrowing of the body posteriorly. 

Historical Review 

The genus was first reported by Stein (1883), who 
figured C. horrida in several views. The larger plates 
of the theca were distinctly shown and the attachments of 
all the six spines correctly indicated. The pattern of the 
major plates is easily established from Stein's figures. 

In the same year this species was described and 
figured by Gourret (1883) under the name Dinophysis 
jourdanii, which later became attached to another spe- 
cies, C. gourretii Paulsen (see p. 43). Schutt (1895) re- 
ported a third species under the name Goniodoma acumi - 
natum var. armatum ; and Cleve (1903) reported another 
species under the name Goniodoma bipes . These last 
three species were later ascribed to their proper genus 
by Kofoid (1910), who appreciated the resemblances of 
their plate patterns to that of Ceratocorys horrida Stein. 

Murray and Whitting (1899) figured, under Cerato - 
corys spinifera , a species of Gonyaulax and a species of 
Ceratocorys . The latter species was renamed C. magna 
in the revision of the genus by Kofoid. This revision, 
thus, included five species. We owe to Kofoid the proper 
allocation of all these forms to the genus Ceratocorys . 
He did not figure any of the species, however, and did not 
analyze the sulcal plate pattern. 

Following Kofoid's (1910) revision, only one possi- 
bly valid species has been introduced, viz., Ceratocorys 
kofoidii Paulsen (1931, p. 36, fig. 22A-C). This species, 
which is related to C. gourretii , was not found in the 
Carnegie collections. Paulsen's sketches do not furnish 
much more than the general body outline. He gives the 
length as 115 microns. This exceeds the length of any 
specimen of the genus Ceratocorys which the author has 
ever measured, the longest being a specimen of C. arma- 
ta, which measured 99 microns. This size can best be 
appreciated if we contrast it with that of C. gourretii , 
which is the smallest species of the genus, and has a 
length of 49 (38-62) microns. In Paulsen's description 
of C. kofoidii it is stated that that species is related to 
C. gourretii, that it differs in the less rounded form, 



FAMILY CERATOCORYACEAE 



37 



higher epitheca, and absence of wings between the spines. 
There is no comment on the extraordinary size, which, 
if correctly given, would be the outstanding character- 
istic of the species. 

The true relationships of this species cannot be de- 
cided until the morphology is known in detail. The spe- 
cies probably belongs to the subgenus Protoceratocorys. 
Ceratocorys kofoidii has not been treated elsewhere in 
this report because of the imperfect knowledge of its 
thecal morphology. 

The present report includes seven species, three of 
which are new. One of Kofoid's (1910) species has been 
listed as uncertain. Furthermore, the species have 
been arranged into two subgenera, the first attempt at a 
subgeneric division of Ceratocorys so far made. 

Systematic Position 

Ceratocorys is probably most closely related to the 
genus Goniodoma . This is indicated especially by the 
number of plates in the two genera and by the patterns 
of their ventral areas (see p. 6). 

Ceratocorys is characterized by 29 plates, the 
smallest number found among the genera investigated in 
this report (see p. 7). The number of epithecal plates, 
including the apical closing platelet, is only 10; and the 
number of hypothecal plates is only 8. There are 6 gir- 
dle plates and only 5 sulcal plates. Goniodoma agrees 
with Ceratocorys in all these particulars except in the 
number of epithecal plates, this being 11 instead of 10. 

The actual relationship of these two genera is prob- 
ably not so close as the agreement in the number of 
plates suggests. For instance, although the number of 
hypothecal plates is the same, the tabulation is quite 
different: Ceratocorys has 6 postcingulars (2 of which 
are minute), 1 small intercalary, and 1 antapical; Goni - 
odoma has 5 postcingulars (subequal in size), no inter- 
calates, and 3 antapicals. 

The relationship of Ceratocorys to Goniodoma is 
perhaps better demonstrated by the tabulations of the 
ventral areas, a fact particularly evident from the spe- 
cies of Ceratocorys with a short flagellar pore, such as 
C. armata (cf. figs. 1, 53). The pattern of Ceratocorys 
approaches that of Goniodoma more than that of any oth- 
er genus investigated, but differs from it in the follow- 
ing features: in Goniodoma the sulcal ring is complete; 
the posterior sulcal plate touches the pore; and the left 
sulcal plate is large and forms the left side of the pore. 

The ventral areas of these two genera further agree 
in their simplicity of contours, although in Ceratocorys 
the area is narrower and there is a very definite depres 
sion of the left side to form a sulcus, whereas in Gonio - 
doma the area is almost flat and a sulcus proper is ab- 
sent. 

In the presence of the ventral epithecal pore, Cera - 
tocorys resembles not only Goniodoma but also Gonyau - 
lax and other related genera. Since there seems to be no 
uniformity among the various genera as to which plate 
bears this pore, the position of this structure in Cerato - 
corys may be of no value in indicating relationships. 

Ceratocorys is not closely related to any genus oth- 
er than Goniodoma (see p. 8). 



Relationships of the Species 

In a discussion of the interspecific relationships, 
we have to deal with the following morphological char- 
acters: degree of angularity of body; bipedal hypotheca; 
number of major hypothecal plates; number of sulcal 
plates; number of hypothecal spines; presence of dorsal 
and ventral spines; and presence of brush spines. 

On the basis of the most fundamental of these char- 
acters, the difference in plate pattern, we can group the 
species into two subgenera: Protoceratocorys n.subgen. 
and Euceratocorys n.subgen. Protoceratocorys has pol 
in the sulcal complex, so that there are 6 functional sul- 
cal plates and only 5 postcingulars. Euceratocorys has 
pol definitely in the postcingular series, so that there 
are 5 sulcal plates and 6 postcingulars. 

Protoceratocorys includes two species: C.skogsber- 
gii and C. gourretii . Ceratocorys skogsbergii has an an- 
gular body and no dorsal or ventral spine; C. gourretii 
has a rounded body and dorsal and ventral brush spines 
as well as four antapical brush spines. It is thus evident 
that the two species of this subgenus are distinct. 

Euceratocorys includes five species: Of these C. 
horrida is isolated by being the only one with dorsal and 
ventral spines, and brush spines. It is further separated 
from the other species of the subgenus by its angular 
body, extreme development of lists, and low epitheca. 

Ceratocorys bipes is unique in its bipedal body shape 
and in the presence of only two antapical spines. Cera - 
tocorys aultii is a small species with four antapical 
spines and with body little compressed posteriorly. 
Ceratocorys armata and C. reticulata are the only two 
species of the genus which show close mutual relation- 
ships. They are both compressed posteriorly and have 
three or four antapical spines. 

The evolution in this genus, thus, has been very di- 
vergent (see fig. 46). The ancestral form of the genus 
probably was small, spherical, and with four simple ant- 
apical spines. If this assumption is correct, there has 
been, in the subgenus Protoceratocorys, the development 
of the angular body and reduction of spines in C. skogs - 
bergii ; on the other hand, there has been a retention of 
the primitive body shape but development of brush and 
dorsal and ventral spines in C. gourretii, the two spe- 
cies having separated at an early time. 

Of the five species in the subgenus Euceratocorys, 
C. aultii may be considered the most primitive, having 
four antapical spines and rather rounded body. Cerato - 
corys armata and C. reticulata have developed only in 
size and toward a more pointed antapex. Ceratocorys 
bipes represents a trend toward bilobed antapex and loss 
of all but two spines, which are somewhat more devel- 
oped than in the primitive species. Ceratocorys horri - 
da has reached the highest development of angularity of 
body and development of spines and lists. It probably 
was separated from the primitive form at an early date. 

It will be noted that the tendency to develop dorsal 
and ventral spines is correlated with the tendency to de- 
velop brush spines of considerable length. These devel- 
opments occur in both subgenera: in the very small ro- 
tund species, C. gourretii, and in the large angular spe- 
cies, C. horrida . This must be considered convergence, 



38 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



as the plate patterns of these two species exhibit sub- 
generic differences. 

Ceratocorys is probably a very old genus, a conclu- 
sion suggested by the clear-cut definition of its species 
along divergent lines, and by the high degree of con- 
stancy of the species. Ceratocorys horrida andC. arma - 
ta are the most variable units. It should be noted, how- 
ever, that their variations are not in the nature of tran- 
sitions toward the other species of the genus. 



Artificial Key to the Species of Ceratocorys 

A. Prominent dorsal and ventral spines present as well 
as antapical spines B 

A. Prominent spines developed only on the antapical 
plate C 

B. Small rotund species, diameter 28-55 microns . . 
C. gourretii 

B. Large angular species, diameter 43-92 microns . . 
C. horrida 

C. Hypotheca greatly compressed laterally toward the 
antapex, angle /3 usually greater than 22° ... D 

C. Hypotheca not greatly compressed laterally toward 
the antapex, angle /S less than 22° F 

D. Antapex projected into 2 lobes, antapical spines 2 . 
C. bipes 

D. Antapex not projected into 2 lobes, antapical spines 

3 or 4 E 

E. Surface pitted, i/d ratio usually greater than 1.00 . 
C. armata 

E. Surface coarsely and heavily reticulated, \/d ratio 
less than 1.00 C. reticulata 

F. Antapical spines 4, postcingular 1 clearly visible in 
ventral view C. aultii 

F. Antapical spines 3, postcingular 1 scarcely or not at 
all visible in ventral view .... C. skogsbergii 



Subgenus EUCERATOCORYS n.subgen. 

Sulcal plates five; postcingulars six. First postcin- 
gular plate clearly evident in ventral view without dis- 
section, overhangs flagellar pore. Type species: C. 
horrida Stein. 

Ceratocorys horrida Stein 
(Figures 47-50) 

Ceratocorys horrida Stein, 1883, p. 20, pi. 6, figs. 4-11. 
Schutt, 1895, pi. 6, figs. 25 (1), 25 (2). Murray and 
Whitting, 1899, in part, p. 329, pi. 30, fig. 5b. Oka- 
mura, 1907, pi. 4, fig. 25a-c. Kofoid, 1910, pp. 180- 
181. TSrgensen, 1911b, p. 146. Forti, 1922, p. 78, 
fig. 73. Lindemann, 1925, pp. 99-101, figs. 13-19. 
Mangin, 1926 (1922), p. 71. Dangeard, 1927c, pp. 
342-343, figs. 7a, 8a-c. Issel, 1928, p. 273. Pavil- 
lard, 1916, p. 24, Pavillard, 1931, pp. 100-101, pi. 
3, figs. 17A, 17B. Paulsen, 1931, p. 35. Matzenau- 
er, 1933, p. 452, figs. 20a-20c. 

Dinophysls iourdanl Gourret, 1883, p. 79, pi. 3, fig. 55. 

? Cer atochorris tridentata Daday, 1888, p. 103, pi. 3, 
fig. 3. 

Ceratocorys horrida var. longicornis Lemmermann, 

18d9,p. 350, 571. 

Ceratocorys h orrida forma tridentata Entz, 1902, p. 139, 

figT3T 

Ceratocorys horrida var. africana Karsten, 1907, p. 419, 

"pTr727TigsrT=3: 



Ceratocorys horrida var. extensa Pavillard, 1931, p? 101. 

Matzenauer, 1933, pp. 452, 497, fig. 20d. 
? Ceratocorys hirsuta Matzenauer, 1933, p. 453, fig. 23. 
Peridinium globulus [ lapsus pennae], Lindemann, 1925. 

Dimensions . Length of body Q) 69 (38-97) microns. 
Diameter of body at girdle in ventral view (d) 67 (43-92) 
microns. Greatest diameter of body in this view usually 
just posterior to girdle. Eighty-four specimens meas- 
ured. 

Shape . Body usually longer than broad. The _l/d 
ratio is 1.07 (0.87-1.35). Epitheca low, dome-shaped. 
The e/l_ ratio is 0.24 (0.14-0.31). In apical or antapical 
view, body squarish to circular at girdle. Girdle dis- 
placed about 1 girdle width. Hypotheca very angular, 
four -sided, usually somewhat constricted in the middle. 
Antapex broad, sometimes nearly as broad as girdle 
region, making sides almost parallel. Body longer on 
left side than on right (fig. 47B). Posteroventral shear- 
ing quite marked (fig. 47D, E). The angle /3 was not 
measured for this species because the lateral edges of 
the body were not sufficiently straight to allow an accu- 
rate measurement. 

Plate pattern . Second anterior intercalary narrow 
and sometimes quite hidden between high lists sur- 
rounding it, so that its presence can be determined only 
by dissection. First anterior intercalary may or may 
not be indicated by lists. Left sulcal plate very small 
and placed posteriorly, so that the flagellar pore is long 
and borders the right sulcal plate for haH its length. 

Body wall . Thecal wall regularly covered with pro- 
nounced pits except in intercalary zones. In these zones 
there is an irregular and variable scattering of pores 
and, sometimes, pits and ridges. Ventral epithecal pore 
always present although difficult to demonstrate because 
it is placed between high lists surrounding second ante- 
rior intercalary plate. 

Lists. All body lists well developed. Girdle lists 
very extensive, their width usually exceeding five times 
the girdle width and sometimes almost half the diame- 
ter of body. These lists are strengthened by many nar- 
row irregular ribs, which usually run in from the edge 
of the list (fig. 47C) but may occur in the center of the 
list or run out from the body as well (fig. 49B). Poste- 
rior girdle list usually has fewer of these ribs than the 
anterior (cf. figs. 47 A, 4C). Girdle transverse lists well 
developed (fig. 49E). Right sulcal list usually clear of 
spines. Lists of body spines well developed; those of 
antapical spines may or may not join with each other. 
Body lists of epitheca about 0.5 girdle width in height. 
These along the sutures of the precingulars run out onto 
the girdle list (fig. 47C). 

Spines . The long brush spines in this species are 
very striking and characteristic. There are four antap- 
icals, one dorsal, and one ventral spine. They average 
about 66 microns in length, or about as long as diame- 
ter of body, but may attain a length of 120 microns. All 
spines have "brushes" on their distal half which in 
some cases, in heavily sculptured Individuals, extend to 
the body (fig. 49B). Structure of brushes described on 
page 34. 

Reproduction . Fission line typical of genus (p. 34). 
Since the ventral and dorsal spines are attached to the 
third and fourth postcingulars, which belong to the left 
moiety, and since the antapicals belong to the antapical 
plate, which goes with the rijtht moiety, there is a great 






FAMILY CERATOCORYACEAE 



39 



discrepancy in the appearance of the two daughter cells 
immediately after fission (fig. 48A-I). These new spec- 
imens have frequently been mistaken for taxonomic u- 
nits (see under "Historical," below). 

Reproduction may, possibly, take place by the pro- 
duction of autospores. One specimen was found in sam- 
ple 284, station 50 (fig. 50), which indicated that the en- 
tire shell was newly formed, and similar specimens 
were found in sample 563, station 95. The walls of the 
first specimen were very thin, the pores were small 
without pits, the lists were embryonic, and the spines 
were absent. A slight indication of the formation of two 
of the antapical spines was found in the usual position. 
The size was normal for the adult. This specimen 
strongly suggests that ecdysis of the shell occurs in this 
species and that one or more new individuals are formed 
from the old protoplast with the formation of entirely 
new shells. 

Variation . Although the size of the specimens of the 
Carnegie material varied, these specimens represented 
a homogeneous group and no separations of a taxonomic 
nature could be made on this basis. The same held true 
for the length of spines. Figure 51 shows the distribu- 
tion of the frequency of various horn lengths in Carne - 
gie material. It is evident from this that, so far as horn 
length is concerned, only one species can be detected. 
Lemmermann (1899) described var. longicornis as hav- 
ing a horn length of 60 microns and Pavillard (1931) de- 
scribed var. extensa with horns 120 to 130 microns long. 
Sixty microns is near the average for this species in 
Carnegie material (fig. 51). There are not, however, e- 
nough data in the 120- micron range to test the validity 
of Pavillard's var. extensa . Short-horned forms are 
shown in figures 49D and F; long-horned forms in fig- 
ures 49A, C, and G. 

There is considerable variation in the thickness of 
the thecal walls, in the thickness of the lists and spines, 
and in the ornamentation of the body generally. One fre- 
quently finds strongly sculptured individuals like that 
shown in figure 49B. There is every gradation from this 
to the more delicate forms represented by figure 47. 
These variants are not taxonomically distinct. The heav- 
ily sculptured individuals apparently do not represent a 
response to changed environmental conditions, as no cor- 
relation could be found between their occurrence and 
the hydrographic conditions. In four cases specimens 
with thin and specimens with thick thecae were found in 
the same sample; in five cases such specimens were 
found at the same station. It is probable that the strong 
ornamentation indicates age, and thus that there is a 
continuous accretion of skeletal material in the course 
of the life of the individual. 

Occasionally supernumerary spines are developed. 
These always appear in already existing lists, usually in 
the spine lists as double spines (fig. 49C, F). Some- 
times a spine fails to develop (fig. 49D). Lindemann 
(1925, fig. 18) reports a specimen with only three antap- 
ical spines. The absence of one spine in his figure 19, 
however, may be caused by the particular view of the 
specimen. Karsten's Ceratocorys horrida var. africana 
is a many-spined form. 

Historical . Ceratocorys horrida was first estab- 
lished by Stein (1883, p. 159). Stein's figures are re- 
markable for their clarity and accuracy and far excel 
any illustrations of the genus since published. 

Lindemann (1925, p. 101) apparently was not aware 
of Kofoid' s (1910) revision of the genus. Lindemann 



stated that the tabulation in this species is uncertain and 
variable, and that there are always four precingular 
plates (there are in fact five) and one intermediate plate 
which breaks up into a number of plates, the pattern be- 
ing variable as indicated by the lists crossing this plate. 
As shown by the present investigations, careful dissec- 
tion reveals that the pattern in constant. The number 
of plates in the apical region, as well as in all other 
parts of the theca, does not vary, although the pattern is 
not always indicated by the development of lists across 
the apical region. 

Ceratocorys tridentata Daday (1888) was accepted 
by Entz (1905) and Kofoid (1910) as a short-horned form 
of C. horrida . In the writer's opinion, however, this 
form cannot possibly belong to C. horrida because of its 
elongated shape, high epitheca, and absence of ventral 
and dorsal spines. Indeed, in the figure there is nothing 
to indicate that it even belongs to the genus Ceratocorys . 

Ceratocorys horrida var. longicornis Lemmermann 
(1899) and probably C. horrida var. extensa Pavillard 
(1931) are long-horned variants of no systematic impor- 
tance. Karsten's (1907) C. horrida var. africana , fig- 
ured with eight feathered and two simple spines, is also 
a variant of no systematic importance (see above). 

Dinophysis j ourdanii Gourret (1883) must be includ- 
ed in the synonymy of C_. horrida (see p. 43 under C. 
gourretii). 

Ceratocorys hirsuta Matzenauer (1933) must be 
placed in the list of doubtful species. In his description 
Matzenauer states that the species is similar to C. ar - 
mata but has longer, very tufted spines. His figure (p. 
453, fig. 23), however, shows the body shape and girdle 
lists of C . horrida . There are four antapical spines but 
no dorsal or ventral ones. This specimen is possibly 
the right daughter cell of C. horrida (see p. 36 and a- 
bove). 

Entz, as early as 1905, correctly described fission 
in this species, opinions of later workers notwithstand- 
ing. His indication of the skeletal fission line was cor- 
rect except for details of the sulcal area. 

The form to which Mangin (1926, p. 71) referred 
was probably the left (two-spined) daughter cell, as 
Dangeard (1927c) stated. Mangin's statement reads, 
"La plupart des individus sont caracterises pardepuis- 
santes cornes later ales aux angles de la valve infer i- 
eure, mais il existe des formes divergentes dans les- 
quelles deuxepines tres developpees sont opposees l'une 
a l'autre, les autres e"pines restant tres minces." 

Dangeard (1927c) understood the fission line of this 
species and the significance of the two-spined speci- 
mens. He presented iclear drawings of the left (two- 
spined) moiety although he indicated the fifth precingu- 
lar plate incorrectly as going to the left moiety. 

Pavillard (1931) curiously refused to accept the two- 
spined form as a division form in spite of the clear 
drawings of the fission line by Entz (1905) and Dan- 
geard (1927c) and the statement by Kofoid (1910) that 
' 'short horns appear at fission in the younger parts of 
the skeleton of otherwise long-horned forms." Pavil- 
ard suggested, on the other hand, that these forms 
might be identical with his var. extensa, which is char- 
acterized by the length and straightness of the horns 
rather than by any difference in their number. 

Matzenauer (1933) apparently followed Pavillard's 
interpretation of Mangin, but considered var. extensa 
separate from Mangin's "forme divergente." He gives 
figures under both titles. 



40 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Distribution . Ceratocorys horrida is a widespread 
tropical and subtropical species. It has been found fre- 
quently in the Atlantic (Schutt, 1895; Jorgensen, 1911b; 
Dangeard, 1927c; Pavillard, 1931). It is common in the 
Mediterranean (Gourret, 1883; Daday, 1888; Kofoid, 
1910; Pavillard, 1916; Lindemann, 1925; Issel, 1928). In 
the Pacific it was reported from the open North Pacific 
by Lemmermann (1899), from San Diego by Kofoid (1910), 
and from Japan by Schroder (1906) and Okamura (1907). 
It also occurs in the Indian Ocean (Karsten, 1907; Mat- 
zenauer, 1933). 

In the Carnegie collection the species was found at 
114 stations: 18 in the Atlantic, 96 in the Pacific (fig. 
52). There were 360 records of occurrence; 154 rare, 
162 occasional, and 44 common. It was found less fre- 
quently with increase in depth, with 159 records for the 
surface, 113 for 50 meters, and 88 for 100 meters. 
There were 273 net records and 87 pump records. It 
was found in both hemispheres and in practically all 
months of the year. 

This species occurred at almost all the Carnegie 
stations in the tropics (fig. 52). In the Atlantic it oc- 
curred at all but six stations south of 40° north; in the 
North Pacific it occurred at all but one station south of 
35° north; in the South pacific it occurred at all stations 
north of 34° south except in the regions near South 
America. It was absent in the Humboldt Current at 
three stations near the Galapagos. It was rather uni- 
formly distributed throughout its range; the records of 
"occasional" and "common" were widely scattered 
throughout the tropics. 

The surface temperatures at the stations where it 
occurred at any depth varied from 17°5 to 29°5 C. The 
ranges of hydrographic conditions in situ were as fol- 
lows: temperature, 11°. 4 to 29°5 C; salinity, 29.7 to 37.0 
o/oo; pH, 7.17 to 8.47; phosphate, 2 to 189mgP04/m 3 . 

Although C. horrida is never abundant, it is one of 
the commonest of the tropical peridinians. For this rea- 
son it is an excellent indicator of tropical water. Ac- 
cording to the Carnegie observations the species does 
not endure any great lowering of the temperature and 
consequently would not indicate water of tropical origin 
very far from its source. For instance, in the North 
Atlantic Drift the species drops out suddenly where the 
water temperature at the surface falls below 19° C (sta- 
tion 3). In the cold California Current it was not found 
until the temperature had risen to 19°3 C (station 131). 
South of Easter Island in the southeastern Pacific it a- 
gain dropped out where the temperature fell below 19° C 
(station 58). Off Japan it was not found in water with a 
surface temperature below 23°.2 C. 

These observations indicate that the active repro- 
duction of C. horrida probably does not take place in 
water of a temperature below 20° C and that the organ- 
isms carried into cooler regions seldom survive a tem- 
perature below 19° C. In the region off South America 
this species was conspicuously absent at 13 stations 
where the temperature at the surface was above 19°. At 
these stations the temperatures were mostly between 
19° and 21° although at stations 71 to 74 the tempera- 
tures were from 23°5 to 25°3 C. The absence of C. hor- 
rida from this series of stations can probably be attrib- 
uted to the influence of the Humboldt Current, which is 
composed of water of antarctic origin mixed with water 
upwelling along the coast. The movement of this water 
has a westerly component away from the continent. This 
water is being constantly warmed as it progresses. 



Even though it may reach a temperature sufficiently high 
for Ceratocorys horrida , however, it does not contain 
this species because of the lack of inoculation. Thus, 
the eastern limit of the species in this region is pushed 
westward by the drift from the edge of the Humboldt Cur- 
rent. Inoculation probably takes place along this border 
in an irregular and sporadic nature during fluctuations 
of the dynamic conditions, probably through eddies from 
the Easter Island region. That this type of inoculation is 
probable is suggested by the isolated occurrence of C. 
horrida at station 61a, with a surface temperature of 
17°5, the only record where the temperature was below 
19°. The water in that region must have been a local 
mass very recently detached from the tropical mass to 
the northwest. 

Ceratocorys horrida is probably an important or- 
ganism in the economy of the tropical and subtropical 
seas. It was found throughout the regions where the 
phosphate content of the water was less than 10 mg 
P04/m 3 . At many of these stations the observed values 
were less than 5. The nitrates, it is assumed, were e- 
qually low. The nutrient requirements of this species 
must be extremely low. 

The wide range of salinities in which the species 
was found indicates that the species is not very sensi- 
tive in respect to the salinities found in oceanic condi- 
tions. It occurred in the Panamic region in salinities as 
low as 29.7 o/oo. 



Ceratocorys armata (Schutt) Kofoid 
(Figures 53, 54) 

Ceratocorys armatum Kofoid, 1910, p. 181. 
Ceratocorys armata , Schiller, 1929, pp. 412-413, fig. 

31a, b. Forti, 1922, p. 83, pi. 6, fig. 72. 
Goniodoma acuminatum var. armatum Schutt, 1895, p. 

153, pi. 9. figs. 32(1), 32(2). Lindemann, 1925, p. 

98, figs. 5,6. 
Goniodoma fimbriatum Murray and Whitting, 1899, p. 

3557pl. 27, fig. la, b. 
Ceratocorys spinifera Murray and Whitting, 1899, p. 329, 

pi. 30, fig. 6c. 
Goniodoma armatum , Schmidt, 1901, p. 135. 
Gonyaulax fimbriatum Schroder, 1906, p. 329 



33,* 



? Ceratocorys armata , Matzenauer, 1933, p. 453, fig. 22. 

Dimensions . Length of body (J.) 79 (54-99) microns. 
Diameter (d) 70 (47-93) microns. Greatest diameter of 
body at the girdle. Thirty-five specimens were meas- 
ured. 

Shape . In ventral aspect body roughly ovate to kite- 
shaped (fig. 53A). Thei/d ratio is 1.09 (0.97-1.24). 
Epitheca triangular to high dome-shaped. The e/l_ ratio 
is 0.38 (0.31-0.46). At girdle the body is squarish to 
circular with a ventral depression. Girdle displaced 
about 1.5 girdle widths. Antapex narrow, so that the 
angle /3 is comparatively obtuse: 31° (22°-38°). Hypo- 
theca cut off obliquely so that the ventral end of antapi- 
cal plate is about one-third of the way to girdle from the 
dorsal end. Thus, the body is much more angular in lat- 
eral view than in the ventral aspect (fig. 53D). 

Plate pattern . Right sulcal plate is much longer 
than in other species and extends posteriorly for half its 
length into a shoulder of the posterior sulcal plate (fig. 
53). Left sulcal plate short, so that the right sulcal plate 
touches the flagellar pore. 

Body wall . Thecal wall regularly pitted on all major 
plates except along the suture zones. In these zones 



FAMILY CERATOCORYACEAE 



41 



secondary thickenings running into the lists may devel- 
op with age. There are scattered pores in the sulcal 
area, as is shown in figure 53A. Ventral epithecal pore 
usually not evident without dissection. 

Lists . Width of cingular lists 1.25 to 2.00 girdle 
widths, somewhat greater ventrally than dorsally. 
These lists may bear short delicate ribs in the middle 
or, in heavily sculptured individuals, may have strong 
ribs running from the body to the edge of the lists. Gir- 
dle transverse lists frequently very well developed (fig. 
54C). Lists occur along all the sutures of body plates. 
There is a heavy ridge running along the left edge of the 
right accessory sulcal plate extending from the left pos- 
terior corner of the fifth precingular plate to the flagel- 
lar pore and along the right edge of the pore. 

Spines . Dorsal and ventral spines absent. Antapi- 
cal spines three or four (figs. 53E, 54B, D). One list of 
ventral antapical spine usually continuous with left sul- 
cal list. The right antapical spine near but not at the 
junction of po5, po6, and antl. Dorsally there are two, 
rarely one, spines. When two, these spines are joined 
by a list. These dorsal antapical spines are independ- 
ent, i.e., they are not attached to the marginal lists of 
the antapical plate as is the case with the other species 
of the genus. At various curvatures of the body lists, 
particularly at apex and antapex, there are apparent but 
not real spines, especially in strongly sculptured indi- 
viduals. 

Reproduction . Division is typical of the genus. 
Both right and left daughter cells have been found. A 
daughter cell with new right moiety is shown in apical 
view in figure 53C. 

Variation . There is the usual variation in the thick- 
ness of the walls and extent of surface sculpturing due 
to age. Figure 54A, and B shows a specimen in which 
the entire theca, including the intercalary zones, is 
composed of thick, heavily ornamented walls. The two 
dorsal antapical spines may be situated near the cor- 
ners of the antapical plate or more or less close togeth- 
er (fig. 54D); or they may be fused into one in the cen- 
ter of the dorsal side of this plate (figs. 53E, 54E). The 
girdle lists may be entirely without spines or they may 
have short, thickening ribs running from the outer edge 
or may have heavy ribs extending from the body. 

Historical . This species was first described by 
Schutt (1895), iwho figured a form with two dorsal antap- 
ical spines under the name Goniodoma acuminatum var. 
armatum . Goniodoma fimbriatum Murray and Whitting 
(1899) is identical with this species. The apical view 
of Ceratocorys spinifera Murray and Whitting (pi. 30, 
fig. 6c) probably also refers to this species. These au- 
thors' apical view of a "mature specimen" (pi. 30, fig. 
6d) may belong to this species. It is peculiar only in its 
large size. It is 142 microns in diameter according to 
the magnification given by these authors. The widest 
specimen in the Carnegie collection is 93 microns, the 
mean is 70 microns. Kofoid (1910, p. 182) described a 
new species, C. magna , on the basis of this figure. It 
does not seem desirable to retain this name among the 
valid species, as there is always the possibility of a 
mistake in magnification and there is no other feature 
of this figure to distinguish it from C. 'armata . Kofoid 
(1910, p. 181) was the first to bring C. armata under the 
genus Ceratocorys, where it properly belongs. Linde- 
mann (1925), however, was apparently unaware of Ko- 



foid's (1910) revision and lists it under the Schiittean 
designation (p. 98, figs. 5, 6). He states that the plate 
pattern is a little uncertain and questions the position of 
the form in the genus Goniodoma . He even suggests a 
relation to the genus Phalacroma . Matzenauer's C. ar - 
mata (1933, fig. 22) must be considered questionable. 
The hypotheca is too long for this species; only two 
spines are indicated; and, all together, the figure gives 
the impression of representing an undeveloped speci- 
men. 

Distribution . Ceratocorys armata is a widespread 
tropical and subtropical species. It has been reported 
from the Atlantic by Schutt (1895), Murray and Whitting 
(1899), Schmidt (1901), Pavillard (1931); from the Medi- 
terranean by Schmidt (1901), Schroder (1906), Kofoid 
(1910), Pavillard (1916), Issel (1928), Lindemann (1925), 
Schiller (1929), Forti (1922); from the Pacific by Schmidt 
(1901), Lemmermann (1904), Kofoid (1910); andfromthe 
Indian Ocean by Schmidt (1901), Schroder (1906). 

In the Carnegie collection this species was found at 
79 stations: 11 in the Atlantic, and 68 in the Pacific. 
There are 163 records of occurrence: 94 rare, 60 oc- 
casional, and 9 common. It was found less frequently 
with increasing depth. There are 87 records for the sur- 
face, 41 for 50 meters, and 35 for 100 meters. There 
are 117 net records and 46 pump records. The species 
was found in both hemispheres and in all months but 
June. The species was rather widespread at the tropical 
and subtropical stations (fig. 52). In the Atlantic it did 
not occur north of 40° north; and in the Pacific it oc- 
curred between 35° north and 35° south latitude. 

The surface temperatures at the stations where the 
species occurred at any depth varied from 19°to29°.4C. 
The ranges of hydrographic conditions in situ were as 
follows: temperature, 14°.3 to 29°.4 C; salinity, 30.0 to 
36.8 o/oo; pH, 7.80 to 8.39; phosphate, 2 to 151 mg 
P04/m 3 . 

Ceratocorys armata was found almost entirely with- 
in the range of C . horrida, and its distribution is prob- 
ably limited by the same factors that limit the latter 
species. It is a much rarer form than C. horrida , so 
that its records of occurrence are not so continuous. 
This does not necessarily mean, however, that its oc- 
currence is sporadic. Its occurrence outside the range 
of C. horrida was in the southeastern Pacific betwe.en 
Easter Island and South America at stations 62, 63, and 
64a, where the surface temperatures were between 19° 
and 20°. This exception probably was due to a local in- 
oculation of this general region similar to that of C . hor- 
rida at station 61a. 

The data indicate that C. armata is more limited to 
the warm water than is C. horrida . The species is not 
found regularly enough within its range, however, to al- 
low us to consider as really significant the negative rec- 
ords along the limits of the distributional area. It oc- 
curred in the North Atlantic Drift as far to the north as 
did C . horrida , viz., to station 2, where the temperature 
was 20°.5. Beyond the California Current it did not ap- 
pear until a surface temperature of 22° 9 was attained; 
off Japaniit did not occur where the temperature of the 
surface water was less than 23°. 9; and south of Easter 
Island it was found as far south as station 57, where the 
surface temperature was 19°0. It is not sufficiently 
common to be of great value as an indicator of tropical 
water; its presence is significant but not its absence. 



42 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Ceratocorys reticulata n.sp. 
(Figure 55) 

Dimensions. This is the largest species of the ge- 
nus. Length of body (_1) 93 (84-98) microns. Diameter 
of body (d) 99 (86-114) microns. Greatest diameter of 
body is at the girdle. Four specimens were measured. 

Shape . In ventral aspect the body is almost dia- 
mond-shaped, somewhat truncated posteriorly (fig. 55A). 
This species is unique in that the body width always ex- 
ceeds the length; i/d ratio is 0.94 (0.86-0.97). Epitheca 
subcorneal, the highest of any species of the genus. The 
e/1 ratio is 0.42 (0.40-0.46). Thus, the girdle is nearly 
equatorial. At girdle, body is nearly circular with a de- 
pression ventrally (fig. 55B). The wide girdle region 
and almost pointed antapex result in a comparatively ob- 
tuse angle /3, the greatest of the genus: 37° (38°-39°). 
The two sides of hypotheca nearly equal in length. An- 
terior displacement of ventral side of antapex very small 
(fig. 55C). Girdle displaced about 1 girdle width. 

Thecal wall . Surface completely covered with a 
heavy reticulation except in parts of ventral area and on 
the posterior intercalary plate. Pores could not be dem- 
onstrated in the meshes of this network nor in the girdle. 

Plate pattern . Left sulcal plate extends sufficient- 
ly far forward so that the right sulcal plate does not 
touch flagellar pore. 

Lists . Girdle lists short, approximately 1 girdle 
width wide, strengthened with regularly spaced ribs run- 
ning from the body completely to outer edge. These ribs 
are continuous with the girdle transverse lists and di- 
vide girdle into a series of chambers. Body lists typi- 
cal of genus. All sutures clearly indicated by low lists 
or thick ridges. Right sulcal list usually supported by 
several heavy spines (fig. 55C). 

Spines . Dorsal and ventral spines absent. Antapi- 
cal spines simple, three in number; one of them ventral 
at posterior end of sulcus, the other two dorsal. The 
latter are connected with the antapical lists by their own 
connecting lists (fig. 55D). 

Reproduction . Division stages were not found. In 
the specimen shown in figure 55, however, the lists of 
the right half of the body were not all well developed, in- 
dicating a certain degree of immaturity of the specimen. 

Variation . The species is constant. Variations in 
size and shape have already been given above. 

Distribution . In the Carnegie collection this species 
was found at 30 stations: 1 in the Atlantic, 29 in the Pa- 
cific. There are 41 records of occurrence: 36 rare and 
5 occasional. The species was found somewhat more 
often at 50 meters than at other depths, with 9 records 
for the surface, 20 for 50 meters, and 12 for 100 me- 
ters. There are 4 pump records and 37 net records. 
The species was found in both hemispheres and from 
September to May. 

Ceratocorys reticulata is a distinctly tropical spe- 
cies. Although it occurred at scattered stations as wide- 
ly separated as Guam and Panama, it was not found 
north of latitude 30° north in the North Pacific nor south 
of 18° south in the South Pacific (fig. 52). In the Atlanticit 
occurred at 13° north, in the North Equatorial Current. 

The surface temperatures at the station where the spe- 
cies occurred^: any depth varied from 20 °.4 to 29°.5 C. The 
ranges of hydrographlc conditions in situ were as follows: 
temperature, 19°5 to 29°.3C; salinity, 30.0 to 36.3 o/oo; 
pH, 8.09 to 8.42; phosphate, 3 to 60 mg PO4/111 3 . Type 
locality: Carnegie station 28. 



Ceratocorys aultii n.sp. 
(Figure 56) 

Dimensions . Length of body (J.) 68 (63-71) microns. 
Diameter (d) 61 (55-65) microns. Three specimens 
were measured. 

Shape . Similar in general appearance to C. skogs - 
bergii , which belongs to the subgenus Protoceratocorys . 
Slightly longer than wide. The J/d ratio is 1.11 (1.09- 
1.15). Epitheca high dome-shaped to subcorneal. The 
e/1 ratio is 0.35 (0.30-0.38). Girdle displaced about 2.5 
girdle widths. Body almost circular in apical view. 
Antapex broad; angle /3 thus comparatively acute: 21° 
(20°-21°). Posteroventral obliquity pronounced (fig. 
56D). In specimens with wide intercalary zones, the 
dorsal antapical spines are displaced ventrally so that 
there is a flattening of the antapex dorsal to the spines 
which produces a superficial resemblance to C. skogs - 
bergii (fig. 56D). 

Body wall . Surface regularly covered with small 
pits. Intercalary zones covered with a faint network of 
large reticulations. Ventral epithecal pore inconspicu- 
ous. Pores scattered in sulcus (fig. 56A). 

Plate pattern . Left sulcal plate extends anteriorly 
so that the right plate is quite remote from flagellar 
pore (fig. 56A). 

Lists. Girdle lists of medium width; about 1.5 to 
2.0 girdle widths wide. Strengthening ribs usually not 
well developed. Transverse girdle lists, however, well 
developed, as are sulcal lists. General body lists not 
well developed. 

Spines . Dorsal and ventral spines absent. Four 
antapical spines at the four corners of antapical plate. 
Spines simple, about 3 to 4 girdle widths long. The dor- 
sal and left members connected by a common list (fig. 
56A, B, D), as are sometimes the ventral and right 
spines. Left sulcal list runs onto ventral antapical 
spine. Ventral and left sometimes closely approximat- 
ed. It is not unlikely that in some specimens these 
spines may be fused into one spine, considering that this 
condition is sometimes found in C. armata, of which 
much more material is available. 

Reproduction . Daughter cells were not found. 

Distribution . In the Carnegie collection this species 
was found at 15 stations, all in the Pacific. There are 
21 records of occurrence, all rare. The species was 
found more frequently with increasing depth, with 5 rec- 
ords for the surface, 6 for 50 meters, and 10 for 100 
meters. There are 14 net records and 7 pump records. 
The species was found in both hemispheres; during Jan- 
uary to May in the southern hemisphere, in September 
and October in the northern hemisphere. 

The stations at which this species was found are in 
widely-scattered regions of the North and South Pacific 
(fig. 52). Three of these stations are east of Guam; 
four between San Francisco and Hawaii; four near the 
Samoan Islands; one east of the Tuamotus; and three 
south and east of Easter Island. 

The surface temperatures at the stations where the 
species occurred at any depth varied from 16°. 9 to 
29°.5 C. The hydrographic conditions in situ were as 
follows: temperature, 14°3 to 29°3 C; salinity, 34.4 to 
36.3 0/00; pH, 8.05 to 8.39; phosphate, 3 to 46 mg 
P04/m 3 . 

Ceratocorys aultii is a rare, tropical species, prob- 
ably widespread in tropical waters but seldom collected 
because of its sparse population. Its greatest abun- 



FAMILY CERATOCORYACEAE 



43 



dance may be below 100 meters, since in the Carnegie 
observations its frequency of occurrence increased with 
depth to that level. The species was found within the 
geographic range of C. horrida, except in the southeast- 
ern Pacific, where there were two stations (stations 62 
and 65) outside that range. The correlation of its dis- 
tribution with water of temperatures above 19° was clos- 
er than in the case of C. horrida . Nowhere was C. aul - 
tii found where the surface water had a temperature less 
than 19° C. It can live in water of low nutrient content. 
There are eight records of its occurrence in water con- 
taining less than 10 mg PO^/m . Type locality: Car - 
negie station 57. 



Ceratocorys bipes (Cleve) Kofoid 
(Figure 57) 

Ceratocorys bipes Kofoid, 1910, p. 183. Dangeard, 

1927c, pT3l3, fig. 9a. 
Goniodoma (?) bipes Cleve, 1903, p. 371, fig. 2a-d. 
Ceratocorys (?) asymmetrica Karsten, 1907, p. 419, pi. 

47, fig. 9a-d. 

Dimensions . Length of body (1_) 83 (80-88) microns. 
Diameter (d) 73 (70-77) microns. Six specimens were 
measured. 

Shape . Body longer than broad. The J/d ratio is 
1.13 (1.04-1.24). Girdle placed well forward; ends dis- 
placed about 0.5 girdle width. Epitheca low dome- 
shaped. The e/1 ratio is 0.28 (0.24-0.34). Hypotheca 
irregular in shape; roughly squarish in lateral aspect 
but subcuneate in ventral aspect. The angle /3 24° (17°- 
28°). At antapex there are two bulbous swellings, one 
dorsal and one ventral. Each is terminated by a long, 
prominent spine, directed ventrally, giving the species 
its characteristic appearance. Dorsal bulb medially sit- 
uated and involves parts of po4, po5, and antl (fig. 57E). 
Ventral lobe somewhat to the left of median line. It in- 
volves posterior parts of the left side of sulcus and of 
pi, as well as part of po3 and antl. Right side of sulcus 
not involved in this lobe, so that the right ventral con- 
tour of the body in right lateral view approximates the 
typical Ceratocorys shape (fig. 57C). 

Body wall . Thecal surface covered throughout with 
circular pits except on parts of sulcus. Pores could not 
be demonstrated in pits. Ventral epithecal pore incon- 
spicuous. 

Plate pattern . Second anterior intercalary narrow 
and almost hidden between list ridges bordering it. 
Ridge between as and ra rises to touch right edge of pol, 
so that flagellar pore is completely arched over in its 
middle. Left sulcal plate short, so that right sulcal 
plate touches flagellar pore. 

Lists . Girdle lists relatively short, about 1 girdle 
width wide; strengthened by stout spines running out as 
continuations of body wall, almost or entirely to outer 
edges. These ribs are continuous with partitioning lists 
or ridges on girdle plates. Surface of girdle may con- 
sist of two rows of small chambers or, more often, of 
one row of deep chambers with prominent partitioning 
lists (fig. 57A). Sulcal lists and ventral body list are 
quite wide (fig. 57C, D, F) and supported by several 
ribs. Main body sutures usually evidenced by thick 
ridges or wide bands of undifferentiated heavy thecal 
material, the latter probably representing growth zones. 

Spines . Dorsal and ventral spines absent. Antapi- 
cal spines two; they occur at dorsal and ventral corners 



of antapical plate, and appear as long, sharp spines, as 
much as 4 girdle widths long. They are simple but 
formed on the same principle as those of C. horrida 
(p. 33). Ventral component of ventral antapical spine 
usually continuous with left sulcal list. 

Reproduction . Fission probably is typical of the ge- 
nus although no recently divided forms were found. 

Variation . This species is very constant as to size, 
shape of body, and number of spines. One specimen was 
found (fig. 57C), however, in which each antapical spine 
was represented by two short spinelets. 

Historical . This species was first described by 
Cleve (1903) as Goniodoma (?) bipes . Later Karsten 
(1907) hesitatingly placed it in the genus Ceratocorys , 
species asymmetrica . Kofoid (1910) placed it definitely 
in its proper genus. 

Distribution . Ceratocorys bipes is a rare tropical 
species seldom reported. It was recorded once from 
the Red Sea and Arabian Seas (Cleve, 1903), once from 
the Indian Ocean (Karsten, 1907), and once from the 
Atlantic (Dangeard, 1927c). It had not been reported 
from the Pacific before the Carnegie investigations. 

In the Carnegie collection the species was found at 
22 stations: 1 in the Atlantic and 21 in the Pacific. 
There are 31 records of occurrence: 29 rare and 2 oc- 
casional. It was found more frequently with increase in 
depth, with 3 records for the surface, 11 for 50 meters, 
and 17 for 100 meters. The 2 records of "occasional" 
were at 50 and 100 meters. There are 9 pump records 
and 22 net records. 

The single occurrence in the Atlantic was at station 
2, in the North Atlantic Drift (fig. 52). In the Pacific the 
species occurred at widely scattered regions, but all 
records were well within the range of C. horrida . There 
were 2 stations south of Japan, 2 north of Hawaii, 8 in 
the equatorial currents of the central Pacific, and 9 
between the Galapagos and Easter Islands. 

The surface temperatures at the stations where the 
species occurred at any depth varied from 20°. 8 to 
29°, 4 C. The ranges of hydrographic conditions in situ 
were as follows: temperature, 18°2 to 29°.3 C; salinity, 
34.4 to 36.4 o/oo; pH, 7.93 to 8.37; phosphate, 4 to 60 
mg P04/m 3 . 

Ceratocorys bipes is a rare tropical species, per- 
haps widespread but seldom collected because of its 
sparse numbers. It is strikingly restricted to the warm 
tropical water masses, much more so than most other 
species of the genus. Thus, although it was found off 
Japan at latitude 34° north in water with a surface tem- 
perature of 23°2 (station 112), it was not found near the 
influence of either the California Current or the Hum- 
boldt Current. It was found in the southeastern Pacific, 
south of Easter Island, but the temperatures there were 
above 20°. It can live in water low in nutrients; e.g., 
there were six records in water having a phosphate con- 
tent less than 10 mg P04/m 3 . 



Subgenus PROTOCERATOCORYS n.subgen. 

Sulcal plates six, postcingulars five. Sixth sulcal 
plate homologous with first postcingular of Eucerato - 
corys . For this reason the designation pol is retained 
for this plate. This plate is small and is turned down to 
form the left edge of the sulcus along side of flagellar 
pore, and is not evident in the ventral view of an intact 
specimen. Type species: C. gourretii Paulsen. 



44 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Ceratocorys skogsbergii n.sp. 
(Figure 58) 



Dimensions. 



One of the smallest species of the 
Length of body ( 1_) 66 (63-69) microns. Diame- 
Two specimens were meas- 



genus. 

ter (d) 58 (56-59) microns. 

ured. 

Shape . Similar in general appearance to C. aultii 
of Euceratocorys . Body longer than broad. The J/d 
ratio is 1.15 (1.13-1.17). Epitheca of medium height, 
with girdle placed well forward. The e/1^ ratio is 0.33 
(0.32-0.34). Girdle displaced about 0.5 girdle width. 
Body almost circular in apical view (fig. 58B). Hypothe- 
ca squarish at antapex; somewhat constricted near mid- 
dle. Antapex broad, so that sides of hypotheca do not 
converge at a great angle with longitudinal body axis. 
The angle 15.°5 (15°-16°), the smallest of any species 
for which this angle could be measured. The postero- 
ventral corner of antapex is truncated obliquely at an 
angle of about 45° to longitudinal axis (fig. 58D). Dorsal 
hypothecal plates (po4 and po5) extend to and around 
antapex, forming part of the most posterior end of body. 
Antapical plate alone forms the obliquity and is not 
rounded so as to form antapex, as is the case in C. hor - 
rida (fig. 47E). 

Body wall . Surface covered with small pits. Inter- 
calary zones may have small irregular markings and 
pores. Ventral area variously ornamented with reticu- 
lations and pores (fig. 58A). Ventral epithecal pore in- 
conspicuous. 

Plate pattern . Second anterior intercalary some- 
times touches apex and thus becomes, actually, an apical. 
It is usually wide enough to be quite evident. 

Lists . Girdle lists small, about 1 girdle width wide. 
Strengthening ribs regularly spaced, usually running out 
from body wall. When the girdle plates are dissected 
away from the body plates to which the girdle lists are 
attached, an extremely thin membrane is seen to be at- 
tached to the girdle plate. In intact specimens this 
membrane lies in contact with the list. Transverse gir- 
dle lists fairly well developed. Body lists, except the 
ventral one, not well developed. Body sutures may or 
may not be indicated by such lists. The ridge to the 
right of flagellar pore rises to meet pol, forming an 
arch over the posterior part of pore. 

Spines . Dorsal and ventral spines absent. Antapi- 
cal spines three; straight and simple, about 2.5 girdle 
widths long, placed at dorsal, ventral, and left corners 
of antapical plate. They were not connected by lists in 
the specimens examined, although the left sulcal list ran 
onto the ventral spine. 

Reproduction . Evidence of fission was not found. 

Distribution . This species was found at 10 of the 
Carnegie stations, all in the Pacific. There are 11 rec- 
ords of occurrence, all rare. The species exhibited a 
tendency to be more common at the surface, with 5 rec- 
ords for the surface, 4 for 50 meters, and 2 for 100 me- 
ters. There are 2 pump records and 9 net records. 

In its geographic distribution, this species was re- 
stricted to the southern and western Pacific (fig. 52). 
There was 1 station off Japan (station 113), 2 in the 
North Equatorial Current (stations 91 and 100), 4 east 
of Samoa, and 3 southwest of Easter Island. 

The surface temperatures at the stations where the 
species occurred at any depth varied from 22°. 8 to 
28°7 C. The ranges of hydrographlc conditions in situ 
were as follows: temperature, 21 °5 to 28°7 C; salinity, 



34.7 to 36.2 o/oo; pH, 8.22 to 8.39; phosphate, 8 to 40 
mg P04/m^. 

This is a very rare tropical species. There are so 
few records of its occurrence that no distributional cor- 
relation would be significant. There were 2 records of 
its occurrence in water with less than 10 mg P04/m3. 
Type locality: Carnegie station 51a. 



Ceratocorys gourretii Paulsen 
(Figure 59) 

Ceratocorys gourretii Paulsen, 1931, p. 36. 
Phalacroma j ourdanii Schiitt, 1895, p. 64, pi. 4, fig. 20, 

1-4. Entz, 1902, p. 130, figs. 6-8. Entz, 1905, pp 

111, 113, figs. 1-4. 
Ceratocorys horrida, Murray and Whitting, 1899, p. 329, 

pi. 30, fig. 5a. 
Phalacroma Ceratocorys Entz, 1902, pp. 135-144, figs. 

26, 33. Entz, 1905, pp. 120-127, figs. 22-28, pp. 

Ill, 134-142. 
Ceratocorys j ourdanii Kofoid, 1910, pp. 183-185. Forti, 

1922, p. 84, pi. 6, fig. 74. Dangeard, 1927c, p. 343, 

fig. 7b. Pavillard, 1931, p. 101. Matzenauer, 1933, 

p. 452, fig. 21. 
not Dinophysis j ourdanii Gourret, 1883, p. 79, pi. 3, fig. 

55 (=C. horrida Stein). 
? Dinophysis g ales , Pouchet, 1883, p. 28, fig. G, no. 3. 
? Dinophysis j ourdanii , Klebs, 1884. 
? Dinophysis armata Daday, 1888, p. 193, pi. 3, fig. 6. 

Dimensions . Smallest species of the genus. Length 
of body (I) 49 (38-62) microns. Diameter (d) 42 (28-55) 
microns. Greatest diameter of body in ventral view 48 
(34-60) microns. Nineteen specimens were measured. 

Shape . Body unique in its subspherical to obovoid 
shape, with absence of the angularity characteristic of 
other members of the genus. The pronounced curvature 
of the body causes the anterior circumference of the gir- 
dle to be considerably shorter than the posterior (fig. 
59D, E, F, G). Body circular to subovate in apical view 
(fig. 59B), always slightly longer than wide. The h/d 
ratio is 1.22 (1.06-1.57). Angle /3 not measured fortius 
species because of curvature of lateral margins. Epi- 
theca low dome-shaped, with girdle far forward as in the 
genus Phalacroma, with which the species has been con- 
fused. The e/l_ ratio is the smallest in any species of 
the genus: 0.20 (0.16-0.22). Greatest width of body a- 
bout halfway from girdle to antapical margin. Girdle 
displaced about 1 girdle width. 

Body wall . Thecal wall regularly covered with very 
small pits. Ventral epithecal pore conspicuous. In in- 
tercalary zones the pits are either absent or fewer than 
on original portions of plates (fig. 59H). 

Plate pattern . Second anterior intercalary narrow 
and hidden between lists. Sometimes no other plates are 
indicated by lists except at left side of sulcus. First 
postcingular reduced to a small triangular plate joining 
anterior sulcal and second postcingular plates. It forms 
left edge of flagellar pore. Second postcingular more 
distally located than anterior sulcal plate and partly 
overhangs the pore as the first postcingular does in the 
subgenus Euceratocorys . Right accessory sulcal plate 
long. Right sulcal plate comparatively short, so that it 
barely touches flagellar pore (fig. 59A). 

Lists . Girdle lists about 1.5 girdle widths wide, 
strengthened by cross ribs running either from body or 
from outer edge of lists. Partitioning lists on the gir- 
dle not well developed. Right and left sulcal lists al- 
ways quite evident, as are the lists bordering a2 and the 



FAMILY GONIODOMACEAE 



45 



apical pore platelet. Along other sutures of body, lists 
may be absent and dissection is necessary to determine 
plate boundaries. 

Spines . Dorsal and ventral spines present; antapi- 
cal spines three. All spines have "brushes" as in C . 
horrida. Antapical spines located at the ventral, dorsal, 
and left corners of antapical plate. They lie almost in a 
straight line because of the oblong shape of the antapical 
plate (fig. 59C). Their dorsoventral lists are continuous 
(fig. 59D). Autotomy of the spines is common. Figure 
59D shows a specimen with autotomy of the dorsal spine. 

Reproduction . Two daughter cells with old left moi- 
eties were found. These showed mature dorsal and ven- 
tral spines, but the antapical spines were minute (fig. 
59E, G). 

Variation . There is comparatively little variation 
in the shape of this species, although the size is varia- 
ble. The greatest variation is in the spines, which may 
be variously bent, long or short, single or double. Fig- 
ure 59F shows a specimen with a double ventral spine 
and with an extra, simple spine in the dorsal list. Some- 
times the central core of the spine may not extend to the 
body (fig. 15E, G). In such cases the cruciform struct- 
ure of the spines is not developed. 

Historical . This species was clearly figured by 
Schutt (1895, pi. 4, fig. 20, 1-4), who, however, confused 
it with Dinophysis j ourdanii Gourret (1883). Schutt as- 
signed his specimens and Gourret's species to the genus 
Phalacroma , under the name P. j ourdanii . Entz (1902, 
1905) accepted this interpretation and, in addition, made 
the rather strange suggestion that this species repre- 
sented a transition between the genera Phalacroma and 
Ceratocorys . Kofoid (1910) definitely recognized the 
true generic relationship of the Schuttian species and 
placed this form in the genus Ceratocorys . JSrgensen 
(1911b), apparently unaware of Kofoid s revision, ex- 
pressed the opinion that Schutt's species belongs to 
Ceratocorys . Kofoid, however, accepted Gourret's fig- 
ure as representing this form. In the writer's opinion 
Gourret's species (pi. 3, fig. 55) is quite obviously C. 
horrida Stein, reported in the same year. In this re- 
spect the writer agrees with the opinion expressed by 
Paulsen (1931), who proposed a new name, C. gourretii, 
for the Schuttian species. This name should be accept- 
ed, since the name j ourdanii must be relegated to the 
synonymy of C. horrida . Klebs (1884) recognized the 
similarity between Gourret's and Stein's figures, but be- 
lieved that Gourret, rather than Stein, realized its true 
relationship, and thus he preferred the name Dinophysis 
j ourdanii for Stein's as well as for Gourret's species. 
In regard to Gourret's figure, the length of the spines, 
shape of the body, and width of the cingular lists mark 
it off sharply from Phalacroma j ourdanii Schutt and re- 
veal its identity with C. horrida Stein. It resembles the 
former species only in having five spines instead of the 
six characteristic of C. horrida . The left antapical 
spine, however, which is missing in Gourret's figure, 
often extends laterally so that it is not visible in the 
view represented in this figure. 

The writer agrees further with Paulsen (1931) in the 
allocation of the figures of Murray and Whitting (1899, 
pi. 30, figs. 5a, 5b). Figure 5a represents C. g ourretii , 
and 5b belongs to C. horrida . Kofoid (1910, p. 185) 
erred in his reference to figure 5a and omitted any ref- 
erence to figure 5b. 

Distribution . Ceratocorys g ourretii is a rare but 
widespread tropical species. It has been reported from 



the Atlantic by Schutt (1895), Murray and Whitting (1899), 
and Dangeard (1927c). Pavillard (1931) reported it from 
the collections of the cruise of the Prince of Monaco in 
the tropical North Atlantic at 78 stations during the 
years 1887, 1895, 1902-1905, 1908-1910. In the Medi- 
terranean it was reported by Entz (1902, 1905), by Forti 
(1922), by Paulsen (1931), and from 19 stations by 
Pavillard (1931). Matzenauer (1933) found it at 2 sta- 
tions in the Indian Ocean and at 2 stations in the Red 
Sea. Until the Carnegie investigations it had been re- 
ported only once from the Pacific, at San Diego (Kofoid, 
1910). The Carnegie collection has added many new 
records for the Atlantic and Pacific. 

In the Carnegie collection this species was found at 
41 stations: 5 in the Atlantic and 36 in the Pacific. 
There are 77 records of occurrence: 68 rare, 8 occa- 
sional, and 1 common. The species was found more fre- 
quently at the surface than at the lower depths, with 47 
records for the surface, 16 for 50 meters, and 19 for 
100 meters. There were 33 pump records and 44 net 
records. 

In the Atlantic this species was found at 1 station in 
the North Atlantic Drift (station 16) and at 4 stations in 
the North Equatorial Current. In the Pacific it was 
widely distributed in the tropical regions (fig. 52). In 
the western Pacific, however, it did not occur north of 
19° north. North of the Hawaiian Islands it occurred as 
far north as 34° north. In the southeastern Pacific it 
occurred as far south as 32° south. It was not found 
within a thousand miles of either North or South Ameri- 
ca in the Pacific. 

The surface temperatures at the stations where the 
species occurred at any depth varied from 22.°3 to 
28.°7 C. The hydrographic conditions in situ were as 
follows: temperature, 11°.4 to 28.°7 C; salinity, 33.7 to 
36.4 o/oo; pH, 7.76 to 8.39; phosphate, 3 to 60 mgPOVmS. 

Ceratocorys g ourretii is apparently a widespread 
but rather rare tropical species. The Carnegie obser- 
vations indicate that it is confined to purely tropical wa- 
ter. It was never found at a station where the surface 
temperature was less than 22°3, so that it is restricted 
to water warmer than in the case of any other species 
of the genus. Its geographical distribution is, thus, much 
more limited than that of C. horrida . The species can 
develop in water poor in nutrients. There were 21 rec- 
ords of its occurrence in water with phosphate content 
less than 10 mg P04/m 3 . 



Family GONIODOMACEAE Lindemann 

Diagnosis . "Shape somewhat spherical to polygonal. 
Apex present. Girdle quite or nearly equatorial. Ma- 
rine forms, which are distinguished by three antapical 
plates, three apical plates in typical representatives. Of 
the antapical plates, two are ventral, one dorsal. Length, 
as far as known, 40 microns to 94 microns. Only one 
genus." (Lindemann, 1928, p. 94.) 



Genus GONIODOMA Stein 

Diagnosis . See family diagnosis (monogeneric). 

Extent of the genus . The genus, at present, contains 
only one well- authenticated species, G. polyedricum 
Pouchet, which is the only one treated in this report. 
Other species have been reported with very sketchy 



46 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



drawings, e.g., G. ostenfeldii Paulsen (1904), or with no 
drawings at all, e.g., G. crassa and G. reticulata Kofoid 
and Michener (1911). None of these can be included in 
this genus with full certainty until more adequate de- 
scriptions or figures are available. 

Comparisons . The genus Goniodoma is a distinct 
unit with no close relatives (see p. 8). All regions of 
the theca except the girdle are distinctive. The tabula- 
tion of the epitheca is unique. Although other genera 
have been reported with ten epithecal plates, none has 
the combination of three apicals, no intercalaries, and 
seven precingulars. The hypothecal pattern is almost 
equally distinctive. It occurs elsewhere only in the ge- 
nus Pachydinium Pavillard. 

The ventral area substantiates the distinctness in- 
dicated by the larger body plates. The sulcal plates are 
only five and are comparatively simple and flat. The 
ventral area is rather flat and there is no well-defined 
sulcus. The flagellar pore faces ventrally, so that it is 
completely unobscured in ventral view. The ventral 
area, thus, must be considered primitive as compared 
with the highly complex areas of Peridinium and Gon - 
y aulax with their development of intricate plates, deep 
sulcus, and elaborate lists. 

As indicated on page 8, Goniodoma may be consid- 
ered a primitive genus whose closest relative is Cerato - 
corys, although the two genera are quite widely separat- 
ed. 



Goniodoma polyedricum (Pouchet) JSrgensen 
(Figure 60) 

Goniodoma polyedricum Jorgensen, 1899, p. 33. Paulsen, 
1907, p. 8. Paulsen, 1908, p. 33, fig. 42. Paulsen, 
1931, p. 37. Lindemann, 1925, pp. 97-98, figs. 2-4. 
Lebour, 1925, p. 90, fig. 26. Pavillard, 1931, p. 
96. Matzenauer, 1933, p. 452. 

Goniodoma p olyhedricum , *orti, iy22, p. Hb, pi. b, fig. 

75. 
Peridinium p olyedricum Pouchet, 1883, p. 42, pis. 20, 

ZTTTig.ra 
Goniodoma acuminatum Stein, 1883, pi. 7, figs. 1-16, pi. 

8, figs. 1, 2. Butschli, 1885, pi. 52, fig. 5a-c. Schutt 

1887, figs. 13-16. Schutt, 1895, pi. 7, fig. 31, 1-3, 

pi. 8, fig. 30, 1-10. Schutt, 1896, p. 21, fig. 30. 

Aurivillius, 1898, p. 98. Cleve, 1900b, p. 245. 

Entz, 1905, figs. 65, 66. Wang and Nie, 1932, p. 

295, figs. 7, 8. 
Gonyaulax polyedra Okamura, 1907, pi. 5, fig. 35a-c. 
? Peridinium acuminatum Ehrenberg, 1838, p. 254, pi. 

22, fig. I6~: 

Dimensions . Length of body (1) 58 (40-93) microns. 
Diameter (d) 65 (45-100) microns. Width of girdle 4 to 
6 microns. Eighty-two specimens were measured. 

Shape . Body usually somewhat wider than long. The 
1/d ratio is 0.90 (0.77-1.19). Body almost circular at 
girdle but otherwise very angular (fig. 60A, B, H). An- 
gles occur at almost all major body plate sutures. Epi- 
theca angular dome-shaped without apical horn although 
apex is well defined. Hypotheca broadly truncate poste- 
riorly; antapex between one-third and one-half as broad 
as diameter of body at girdle. Girdle nearly equatorial 
sinistral; displaced from 1 to 2 girdle widths; slightly 
concave; no overhang. Girdle continues onto ventral 
area, where its ends are turned sharply posteriorly. 
Ventral area short, broad, and angular, with a short pro- 
jection of the anterior sulcal plate into the epitheca. 
Flagellar pore ovate, on right side of ventral area at 



proximal end of girdle. It is evident in ventral view 
without dissection. Sulcus only slightly developed. 

Plate pattern . Formula: 3ap, 7pr, 6g, 5s, 5po, 
3ant. The three apical plates are about equal in size 
and surround the apical platelet, which covers apical 
pore (fig. 60A). This platelet is oval in shape and is 
placed at an angle of about 45° to the dorsoventral axis 
of the body. Precingular plates of approximately equal 
size except the ventrally placed first and seventh, which 
are about half the size of the others. The six girdle 
plates subequal in size with sutures symmetrically 
placed (fig. 60A). Postcingular plates also approximate- 
ly equal in size, as are the antapicals (fig. 60B). Sec- 
ond antapical composes most of the truncate antapex. 
The first and third antapicals are more ventrally placed, 
and each bounds half of posterior margin of ventral area. 

The ventral area composed of five plates: three 
large posterior plates lying posterior to the girdle, and 
two anterior ones representing extensions of girdle. 
Anterior sulcal plate (as, fig. 60F, G, H) forms anterior 
end and half right edge of flagellar pore and represents 
the proximal extension of girdle into ventral area. It 
has a limb extending into epitheca, posterior to prl. 
The anterior cingular list is continued across it. The 
left, posterior, and right sulcal plates are more or less 
rectangular, of about equal size, and form greater part 
of area. Left sulcal plate forms left edge of pore, the 
posterior plate the posterior edge, and the right sulcal 
plate is not in contact with the pore. Right accessory 
sulcal plate forms an extension of the distal end of gir- 
dle into ventral area. It has a narrow anterior limb 
which extends to anterior sulcal plate to form the right 
edge of pore. Thus, all sulcal plates border the pore 
except the right. 

Surface. Entire body wall, including that of girdle 
and sulcal plates, covered with large pits regularly ar- 
ranged. These have pores in their centers which, in 
optical cross section, can be seen to extend through body 
wall. Thickness of body wall extremely variable and 
depth of pits varies accordingly. Girdle bears two to 
four rows of pits with pores, although only two rows are 
ordinarily visible in ventral or lateral view as outer 
rows are on curved sides of girdle. There is a ventral 
epithecal pore situated on the anterior margin of prl 
(fig. 60D, H). This pore is peculiar in not being covered 
by a platelet or surrounded by a ridge or list. Body 
plates joined by rabbet membranes which are rather 
narrow compared with those in Peridinium . 

Lists . Cingular lists from 1.5 to 2.5 girdle widths 
wide, always somewhat ornamented with spines and re- 
ticulations, which are quite thick (fig. 60C). Posterior 
list usually more heavily sculptured than the anterior 
(fig. 60A, B). Each suture of main body plates marked 
by a thick triangular list ridge. When these are viewed 
along edge of body, they appear as thin lists because of 
their transparency (fig. 60H, I). Along their outer mar- 
gins they may be clear or bear reticulations. Proximal- 
ly, however, they almost invariably bear large reticula- 
tions or pits (fig. 60A, B, H). Lists surrounding ventral 
area do not attain a greater development than that of the 
body lists. No lists occur at sutures between sulcal 
plates except between the left and posterior sulcal plates. 

Variation . The size varies considerably. In our 
material both the length and the width showed a differ- 
ence of over 100 per cent between the smallest and 
largest specimens. Shape of body more constant. Most 
of the material had anj./d ratio less than 1.00; in only 



FAMILY GONYAULACACEAE 



47 



2 of the 82 specimens measured was this ratio more 
than 1.00, viz., 1.03 and 1.19. The broadest specimen, 
with anj/d ratio of 0.77, on the other hand, was connect- 
ed with the mean by a continuous series of intergrades. 
It was at first thought that the smallest specimens rep- 
resented a distinct species, but when the frequency of 
the width of all specimens was plotted, a primary mode 
was found at 65 microns and a secondary one at 45-50 
microns with so many records between that not even a 
variety was indicated on this basis. The thickness of 
the body wall and of the associated lists is variable; 
forms with extremely heavy thecae are common. 

Reproduction . Stein (1883) figured an individual 
containing a resting cyst (pi. 7, fig. 2). He also showed 
an emerging cyst (pi. 7, fig. 9) with the girdle indicated. 
Other figures by Stein represent cysts with two and four 
daughter cells (swarm spores?) with girdles (figs. 11, 
12). Finally, Stein presented (figs. 13-16) specimens 
which he interpreted as representing stages intermedi- 
ate between these young daughters and the mature spec- 
imens. His material was from the Baltic and Atlantic. 
Schutt (1895, pi. 8, fig. 30, 9, 10) shows daughter cells 
with half-old and half-new thecae, also a "double spore" 
(fig. 30, 7). No specimens representing reproductive 
stages were found in the Carnegie material. 

Distribution . Paulsen (1908) stated that Goniodoma 
polyedricum is an Atlantic subtropical species. Lebour 
(1925) also designated it as subtropical. Both authors 
record the species as rare in the Gulf Stream. It is, 
however, a widespread tropical species, as shown by 
the Carnegie and other observations. It was reported 
from the tropical Atlantic by Schmidt (1901) and Pavil- 
lard (1931); from the Baltic by Aurivillins (1896) and 
Abshagen (1909); from the Mediterranean by Schmidt 
(1901), Forti (1922), Issel (1928), and Paulsen (1931); 
from the Pacific by Schmidt (1901); and from the Indian 
Ocean by Schmidt (1901), and Matzenauer (1933). 

In the Carnegie collection G. polyedricum was found 
at 148 stations: 30 in the Atlantic and 118 in the Pacific. 
There are 471 records of occurrence: 280 rare, 178 
occasional, and 13 common. The species was found less 
frequently with increase in depth, with 218 records for 
the surface, 143 for 50 meters, and 110 for 100 meters. 
There are 190 pump records and 281 net records. It 
was found in both hemispheres and in all months of the 
year. 

The species was found at practically every station 
in the tropical and subtropical regions, and it strayed 
beyond these regions much more than did most of the 
other tropical forms (fig. 61). Thus, it was found in the 
North Atlantic Drift as far as the British Isles (station 
6c); in the western Pacific north of 40° north; in the 
eastern Pacific to 37° north; and in the South Pacific to 
40° south. There was no particular center of abundance. 
The records of "common" and "occasional" were scat- 
tered throughout the range. 

The surface temperatures at the stations where the 
species occurred at any depth varied from 12 "4 to 
29?5 C. The ranges of hydrographic conditions in situ 
were as follows: temperature, 10°.6 to 29°6 C; salinity, 
29.7 to 37.1 o/oo;, pH, 7.17 to 8.47; phosphate, 3 to 
198 mg P04/m 3 . 

It can be concluded from Carnegie observations that 
Goniodoma polyedricum is a fairly common, widespread, 
tropical species. It is similar to Ceratocorys horrida 
in this respect, but it extends into water of lower tem- 
perature. Thus, it was found near the British Isles 



where the surface temperature was only 12 °4 C; north- 
east of Japan where the surface temperature was 15°.9; 
off California, in 16°.2 water; and in the southeastern 
Pacific, in 15° water. It occurred at 6 stations where 
the surface temperature was less than 19°. This species 
should be an excellent plankton indicator, as it is ubiq- 
uitous in the tropics and seems to survive transfer to 
cooler regions. It should indicate water masses of 
tropical origin. 

The species apparently suffers no decrease in wa- 
ters of low nutrient content. There were 165 records in 
water with less than 10 mg PO^rn 3 . 



Family GONYAULACACEAE Lindemann 

Diagnosis . "Shape very variable, spherical, angu- 
lar, elongate, sometimes with hornlike processes or 
distinct spines at both ends. Girdle about equatorial, 
often strongly spiraled. Small posterior intercalary 
present. Length, 18 microns to 167 microns." (Linde- 
mann, p. 84, 1928.) 



Genus GONYAULAX Diesing 

Diagnosis . "Body variously shaped, spheroidal, 
polyhedral, broadly fusiform, elongated with stout apical 
and antapical prolongations, or dorso-ventrally flat- 
tened. Apex rounded or truncate symmetrically or a- 
symmetrically, never acutely symmetrically pointed. 
Antapex rounded, flattened, or pointed symmetrically or 
asymmetrically. Girdle usually equatorial, descending, 
displaced distally one to seven times its own width, and 
sometimes with slight overhang. Transverse furrow 
impressed or not; longitudinal furrow usually slightly 
indenting the epitheca, often flaring distally, well devel- 
oped, reaching to or approaching the antapex. Thecal 
wall consisting of one to six apical plates, none to three 
anterior intercalates, six precingulars, six girdle 
plates, six postcingulars, one posterior intercalary, and 
one antapical. The longitudinal furrow occupies the 
whole of the ventral area which slightly indents the epi- 
theca and consists of one anterior, about four interme- 
diate and one posterior plate. The midventral plate of 
the apical series is usually a narrow plate extending 
posteriorly to a junction with the anterior plate of the 
ventral area, thus parting precingulars one and six. 
When guarded by lateral ridges it simulates an anterior 
extension of the longitudinal furrow. It bears at its apex 
a delicate extension, the closing platelet which covers 
the apical region. 

"Surface smooth or rugose with major thickenings 
along suture lines and minor ones on plates forming a 
regular or irregular polygonal mesh of varying size, 
often with vermiculate, longitudinal elements predomi- 
nating, sometimes spinulate. Furrows with or without 
lists which in many species are ribbed or spinulate. One 
or more antapical spines sometimes present, rarely 
with sheathed spines of the Ceratocorys type. Plates 
porulate, with pores in centers, angles, or nodes of the 
mesh. A peculiar large ventral pore occurs to the right 
of the midventral line usually near the suture between 
apical one and the plate to its right. Theca divided ob- 
liquely in fission. Ecdysis frequently seen. Chromato- 
phores yellow to dark brown, often dense. In fresh, 
brackish, and marine waters from boreal to tropical 



48 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



regions." (Kofoid, 1911a, p. 196.) 

Remarks . The present diagnosis of the genus will 
undoubtedly be radically revised upon a more intensive 
study of the morphology of the species now included in 
the genus. Judging from the results of the careful dis- 
section of the two species included in this report, it can 
be concluded that many of the specific diagnoses are 
probably in error. In addition to this, it is likely that 
the genus as now conceived includes several groups of 
generic status. 

In his first diagnosis of this genus, Kofoid (1907b) 
gave the plate formula as 6ap, 6pr, 6po, lant, 1 longi- 
tudinal ventral furrow plate, 1 girdle plate. Apparently 
this analysis was made without dissection of the plates, 
and the many ridges and markings of the theca led to an 
erroneous conclusion as to the plate pattern. Later, 
Kofoid (1911a) stated that his first interpretation was in 
error and gave a new diagnosis which agrees much 
more closely with that found in the two species present- 
ed here. His new formula is "3ap, 0a, 6pr, 6g, 6po, lp, 
lant, ventral area consisting of a narrow anterior plate, 
large posterior plate, and at least three intermediate 
plates." In the present investigations complete dissec- 
tions were made of the entire skeleton of G. pacifica and 
G. fusiformis . The plate formula of these two species 
is as follows: 3ap, 2a, 6pr, 6g, 6-7s, 6po, lp, lant. 

Whedon and Kofoid (1936) made an analysis of two 
new species, G. catenella and G. acatenella . The for- 
mula for each of these is the same, viz., 4ap, 0a, 6pr, 
6g, 5s, 6po, lp, lant. This formula is sufficiently dif- 
ferent from that of G. p acifica and G. fusiformis to jus- 
tify generic separation. Gonyaulax p acifica and G. fusi - 
formis have one less apical, two (instead of no) anterior 
inter calaries, and two more sulcal plates. The facies 
of the ventral part of the epitheca as well as the size 
and shape of the body generally of Whedon and Kofoid' s 
two species is quite different from those of G. pacifica 
and G. fusiformis . 

The present work on the genus Gonyaulax shows 
clearly that a complete reclassification of this and re- 
lated genera is quite necessary. A re- examination of 
the whole group on the basis of thorough morphological 
studies is absolutely essential. Quite new conceptions 
of relationships within the group will undoubtedly result 
from such a critical analysis of extensive material. As 
an example of a realigning, resulting from such thor- 
ough studies, it may be mentioned that G. ceratocoroides 
Kofoid has been placed in a separate genus. 



Gonyaulax pacifica Kofoid 
(Figure 62) 

Gonyaulax pacifica Kofoid, 1907b, p. 308, pi. 30, figs. 37- 
39. Kofoid, 1911b, p. 235, pi. 15, fig. 35. Pavillard, 
1931, p. 51. 

Steiniella cornuta Karsten, 1907, pp. 348, 420, pi. 53, 
HgT7. 

Dimensions . Length of body, exclusive of antapical 
spine (1), 155 (131-263) microns. Transdiameter (d'), 
80 (52-105) microns. This diameter is the greatest di- 
ameter, not the diameter seen in true ventral view (see 
below). Width of girdle, about 5 microns. Twenty-two 
specimens were measured. 

Shape . Body about twice as long as greatest diam- 
eter. TheJ/d' ratio is 1.98 (1.66-2.65). Body extreme- 
ly asymmetrical, probably as a result of a differential 



growth in which the left side has grown decidedly larger 
than the right. The short diameter (d) is about 0.6 
times the long diameter (d') (see fig. 62D). Epitheca 
compressed dorsoventrally, very abruptly from the gir- 
dle so that the distal half of the epitheca extends as a 
bladelike horn (fig. 62A, C, I, J). Hypotheca also very 
strongly compressed dorsoventrally, but here the com- 
pression is accompanied by a strong dorsal curvature 
of the body which results in a concavity on the ventral 
face and in an extreme approximation of the dorsal and 
ventral 'walls of the hypotheca, especially on the right 
side. Thus, the more posterior part of the hypotheca is 
concave blade-shaped and the entire hypotheca is "scoop- 
like" as Kofoid (1911a) described it. Posterior edge of 
body rounded in ventral view with extension on left side 
terminated by a spine which is from 1 to 2 girdle 
widths long. The asymmetrical shape of the body re- 
sults in quite different contours when the body is viewed 
from slightly different angles. Figure 62A shows a 
specimen presenting its widest ventrolateral aspect, and 
figure 62H, a strictly ventral view, presents a narrower 
body diameter but shows the broadest view of the ven- 
tral area. 

Girdle slightly behind the middle; sinistral; ends 
curved ventrally, particularly the proximal end; dis- 
placed 1.5 to 3.0 girdle widths, no overhang; greatly ex- 
cavated, often as much as 1 girdle width (fig. 62B). 

In connection with the unequal development of the two 
sides of the body, there has been a rotation of the long 
axis of the sulcus and ventral area so that in ventrolat- 
eral view only the right side of the ventral area is visi- 
ble. Ventral area more or less elliptical in outline, 
somewhat sigmoid in ventral view but not in the flat ven- 
trolateral view. Anteriorly the area extends into the 
epitheca about 3 girdle widths. Greatest width of area 
attained about halfway to antapex. Posteriorly the area 
tapers to a point about 2 girdle widths from base of ant- 
apical spine. Sulcus a deep groove on left side of ven- 
tral area. Flagellar pore narrow and long (about 3 gir- 
dle widths), sigmoid in outline, following the curvature 
of the ventral area (fig. 62K), and extending posteriorly 
from proximal end of girdle. 

Plate pattern . The three apical plates very unequal 
in size. First apical very narrow with narrow extension 
to girdle (fig. 62C). Apical closing platelet present, 
sometimes loosely attached to anterior end of first api- 
cal plate. Kofoid (1911a) stated that the platelet is a 
definite part of the first apical, but the writer has found 
that it may be detached quite easily. Second apical plate 
is large and composes almost all of distal end of apical 
horn. It has a limb projecting around the apex to right 
side and fitting into a shoulder of first anterior interca- 
lary (fig. 62D, I). Third apical a long triangular plate 
with its apex at apex of specimen and its base along mar- 
gin of second anterior intercalary (fig. 62C, D). This 
apical was shown in Kofoid' s (1907b) earlier drawing, 
but he later (1911a) rescinded his earlier diagnosis of 
this species and omitted this plate. 

First anterior intercalary, a large plate running 
almost to apex, where it has a shoulder into which fits 
the projection of a2. This plate was included in ap3 by 
Kofoid (19Ha), who apparently had not separated it from 
that plate. The second anterior intercalary has not been 
reported before for this species, but was easily deter- 
mined in aU specimens examined. It is probably homol- 
ogous with al in Spiraulax kofoidii. It frequently bears 
a double ridge running transversely across its middle 









FAMILY GONYAULACACEAE 



49 



(fig. 62 A). 

The six precingulars of rather unequal length. 

The six girdle plates subequal in size except for g6, 
which extends from distal end of girdle well around to 
dorsal side of body (fig. 62F); all U-shaped in cross 
section (fig. 62B). 

First postcingular small; anterior to pol; forms 
left edge of flagellar pore (fig. 62C, L). It is similar in 
size and position to pol in Ceratocorys . Second to 
fourth postcingulars larger; subequal in size; occupy 
left ventral and left lateral regions of hypotheca (fig. 
62G). Fifth and sixth postcingulars large; the fifth is 
dorsal, the sixth lateral and ventral. The sixth is ex- 
tremely compressed and forms the lateral keel of hypo- 
theca. 

Posterior intercalary plate, a long narrow plate ex- 
tending from pol along left edge of sulcus to antapical 
plate (fig. 62A, C, H, G, L). It bears the wide left sulcal 
list. 

The antapical plate constitutes the compressed ant- 
apex. A corner of it extends almost halfway to girdle on 
left side of body (fig. 62J). Other margins of this plate 
more limited, especially ventrally, where a narrow 
strip only 1 girdle width wide is visible (fig. 62C). This 
plate bears the antapical spine at its left ventral corner. 

Ventral area composed of seven plates (fig. 62K, L); 
anterior, posterior, right, left, right accessory, poste- 
rior accessory, and intercalary. The anterior sulcal 
plate consists of two inseparable parts. Posterior part 
roundish, with semicircular notch posteriorly which rep- 
resents anterior edge of flagellar pore. Anterior part 
is a process extending into epitheca between base of 
first apical and sides of a2 and pr6 (fig. 62C). Posteri- 
or sulcal plate large, subtriangular, with oblique base 
anteriorly where it borders left and intercalary sulcal 
plates. Remaining five sulcal plates lie between the 
anterior and the posterior; three on the right side, one 
on the left side, and one in the middle. Those on the 
right side, reading posteriad, are the right accessory, 
right, and intercalary. Of these, the right accessory 
and part of the right constitute the right edge of flagel- 
lar pore. Posterior edge of pore formed by tip of pos- 
terior accessory, which lies between rs, i, and Is, but 
does not touch ps. Part of left edge of the pore formed 
by extension of Is; the rest by pol. Thus, all sulcal 
plates touch the pore except the intercalary and posteri- 
or. 

Body wall . Many prominent narrow lists run longi- 
tudinally along body; some run whole length of epitheca, 
others extend only a short distance from girdle. Most 
of these "ridges' bear no relation to sutures although 
they have been so confused in the past. Sutures are often 
marked by low, narrow ridges; sometimes one on each 
side of intercalary zones. Second anterior intercalary 
frequently has a double line, indicating some sort of 
zone, running transversely through its middle. 

A ventral epithecal pore occurs on left anterior cor- 
ner of second anterior intercalary plate. Apical pore 
covered by closing platelet. Minute tubercles are scat- 
tered over major plates rather irregularly, although 
they have a tendency to be arranged in rows. Kofoid 
(1911a) interpreted these as pores. Some of the sulcal 
plates may have similar tubercles or, sometimes, faint 
reticulations (fig. 62A). Girdle plates crossed trans- 
versely by a varying number of ridges, usually spaced 
about 0.5 girdle width apart. 

Lists . Although there are an excessive number of 



body lists in this species, the usual list systems are 
rather poorly developed. Girdle lists small or absent, 
never over 0.5 girdle width wide. Ribs and other struc- 
tural differentiations are absent on these lists. The 
only wide list of the species is the left sulcal list, which 
in the broad ventrolateral aspect of body covers half of 
ventral area posterior to distal end of girdle (fig. 62 A). 
It is attached to right and anterior edges of posterior 
intercalary plate (fig. 62L). Right sulcal list absent on 
hypothecal part of ventral area, but the anterior right 
sulcal list is well developed. It occurs on right edge of 
epithecal extension of ventral area and is attached to 
pr6. In apical view it is visible as a "spine" at distal 
end of girdle (ar, fig. 62D). The body list along right 
keel of hypotheca is well developed and may attain a 
width greater than 1 girdle width. 

Antapical spine often curved to the right. Its length 
varies considerably, viz., from 0.8 to 2.2 girdle widths. 
It may bear small lists or large reticulations. 

Variation . In thin-walled specimens the second 
anterior intercalary usually is quite hyaline and struc- 
tureless. This may be the reason why this plate has 
previously gone unnoticed, for in such cases it may eas- 
ily be mistaken for a wide intercalary zone if careful 
dissections are not made. 

There is considerable variation in shape of body; 
for instance, the degree of compression in the girdle 
region may be low (see fig. 62E), and the antapex may 
be extended as a slight horn (fig. 62H). 

Distribution . Gonyaulax pacifica is a rare, seldom 
reported species, although it has a wide distribution 
over the tropical seas. Pavillard (1931) reported it 
from the Atlantic and from the Mediterranean (1909, 
1931). Previous to the Carnegie cruise it had been found 
in the Pacific only at San Diego (Kofoid, 1907b) and in 
the Indian Ocean only by Karsten (1907). Bohm (1936) 
states it # had never been found in the western Pacific, 
and Matz'enauer (1933) did not find it in the Indian Ocean. 

In contrast with this apparent rarity, the species 
was found at 77 Carnegie stations: 15 in the Atlantic and 
62 in the Pacific. There are 163 records of occurrence: 
140 rare and 23 occasional. It was never common or 
abundant. It was found less at the surface than at the 
lower levels, with 19 records for the surface, 73 for 50 
meters, and 71 for 100 meters. There are 107 net rec- 
ords and 56 pump records. It was found in both hemi- 
spheres and in practically all months of the year. 

Gonyaulax p acifica was found rather consistently 
throughout the tropics, although there are many gaps in 
its distribution (fig. 61). In the Atlantic it was found at 
all stations south of station 15, although not at station 
24 or in the Caribbean. Although the records are not 
continuous south of 40° north, it was not found north of 
that latitude. 

In the Pacific the records are even less complete 
than in the Atlantic. There is no significant geographic 
grouping of the record stations, however, and it is prob- 
able that the species is more uniformly distributed than 
the present records indicate. It is equally common in 
the western Pacific and in the eastern Pacific. It was 
not found north of latitude 35° north nor south of 32° 
south. 

Although the Carnegie records do not show a con- 
tinuous distribution in the tropics, the limits of the dis- 
tribution of the species show a close correlation with the 
surface isotherm of 20° C (fig. 61). At the stations 
where the species was found, the surface temperatures 



50 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



were above 20° C, except at station 66, where the tem- 
perature was 19°. 4 C. 

On the basis of these data, G. pacifica must be con- 
sidered a strictly tropical species which does not endure 
transfer to colder regions. For this reason it is a good 
indicator of tropical water masses, although not so good 
as Ceratocorys horrida because of its less frequent oc- 
currence. 

Water of low nutrient content is no barrier to the 
species, as there are 89 records of its occurrence in 
water with less than 10 mg P04/m^. 

The surface temperatures at the stations where the 
species occurred at any depth varied from 19 °4 to 
29 °4 C. The ranges of hydrographic conditions in situ 
were as follows: temperature, 1°4 to 29°.3 C; salinity, 
33.4 to 37.1 o/oo; pH, 7.17 to 8.39; phosphate, 3 to 121 
mg P04/m 3 . 



Gonyaulax fusiformis n.sp. 
(Figure 63) 

Dimensions . Length of the body (1_), excluding ant- 
apical spine, 86 (67-98) microns. Diameter (d), 47 (35- 
57) microns. Width of girdle, 4.8 (4-5.5) microns. 
Length of antapical spine, 17 (12-23) microns. Seven 
specimens were measured. 

Shape . Body broadly fusiform. The J/d ratio is 
1.82 (1.68-1.98); thus body may be almost twice as long 
as wide. Epitheca extended into a long apical horn equal 
in length to rest of epitheca. Apex somewhat less than 
1 girdle width in diameter. On left side, body tapers 
gradually from girdle to apex, but on right side there is 
a prominent shoulder as in Spiraulax. Hypotheca tapers 
uniformly to antapex except for a constriction about 3 
girdle widths from base of antapical spine (fig. 63D, E, 
G). Body circular in girdle section (fig. 63B, F). Gir- 
dle approximately equatorial, sinistral, displaced from 
1.5 to 2.5 girdle widths, slightly concave; usually with 
no overhang. Ventral area very narrow, usually almost 
straight posteriorly, but bends to left anteriorly; some- 
times slightly sigmoid. Posteriorly it flares out into an 
elliptical area, similar to, but not so wide as, that in 
Spiraulax . Anterior sulcal plate has an extension into 
epitheca (as, fig. 63B). Flagellar pore a long, narrow 
slit situated at left edge of ventral area between dis- 
placed girdle ends and continued posteriorly about 1 
girdle width. 

Plate pattern . The three apical plates quite unequal 
in size. First apical is long, narrow, and curved, and 
extends from apex to anterior sulcal plate on ventral 
side of epitheca (fig. 63E). Second apical extends from 
first apical around to dorsal side of body (fig. 63B); at 
apex it has a limb (x, fig. 63B). about 1 girdle width 
wide which fits into a shoulder formed by the withdrawal 
from the apex of the first anterior intercalary plate. 
This process meets a similar process from the third 
apical (y, fig. 63B, G). Body of third apical linear, ex- 
tending along right side of distal half of first apical. 
Therefore it lies between the first and second apicals 
and between the apex and the two anterior intercalary 
plates. The two anterior intercalates make up the 
greater part of right side of apical horn. The second of 
them is on ventral face of body touching six different 
plates, including first and third apicals, sixth precingu- 
lar, and anterior sulcal plates. The six precingulars 
are of approximately equal width except the first, which 



is somewhat wider. 

The six girdle plates approximately equal in length, 
with sutures as shown by arrows in figure 63A. 

The six postcingular plates are about equal in width 
except the first, which is small and narrow and lies 
along left edge of flagellar pore (fig. 63E, F). A single 
antapical plate extends almost halfway up the right side 
of sulcus. It bears the heavy antapical spine and 4he 
"sulcal spine" (fig. 63F, G). The posterior intercalary 
forms the left edge of ventral area posterior to first 
postcingular. 

Ventral area composed of six plates: anterior, pos- 
terior, left, right, right accessory, and intermediate 
(fig. 63C). Posterior accessory absent. Sulcal plate 
has a projection into epitheca which meets the first api- 
cal plate. A notch in posterior end of this plate repre- 
sents anterior edge of flagellar pore as in G. p acifica . 
Posterior sulcal plate comprises the expanded elliptical 
posterior part of ventral area. It extends to within 1 
girdle width of distal end of girdle. Left sulcal plate 
forms posterior edge of flagellar pore and has a process 
extending anteriorly along left edge of pore to meet first 
postcingular plate, which also borders pore. Right and 
right accessory plates form right edge of flagellar pore; 
the right is opposite distal end of girdle; the right ac- 
cessory is anterior to this. Intercalary sulcal plate is 
small, square, posterior to right plate, and removed 
from flagellar pore. 

Thus the flagellar pore is bounded by the first post- 
cingular and four sulcal plates: the anterior, left, right, 
and posterior accessory. The intercalary and posterior 
sulcal plates do not touch the pore. 

Thecal wall . All plates of body except some of sul- 
cal plates covered with a fine areolation which extends 
completely to edges of plates. Most plates also bear a 
few large, irregularly scattered pores, which, in optical 
section, can be seen to pierce the body wall. They oc- 
cur on the anterior, posterior, and left sulcal plates, but 
frequently occur only in rows along the edges or ridges 
of the narrower plates. One row occurs along each edge 
of girdle plates. 

Intercalary zones occur along most of sutures and 
are marked by a fine areolation and absence of pores. 
Body ridges usually some distance from sutures, and the 
intervening space may be considered the intercalary 
zone, as it is probable that the ridge represents the o- 
riginal suture line. 

The ventral epithecal pore so characteristic of Gon - 
yaulax is present here at left anterior corner of second 
anterior intercalary plate. Apical pore closed by a very 
hyaline apical closing platelet. 

Lists . Girdle lists about 0.75 girdle width wide, 
usually strengthened by simple ribs extending from body 
to the edge of the list, spaced from 0.5 to 1 girdle width 
apart (fig. 63A). Girdle plates free of ridges. Right and 
left sulcal lists present. Posterior part of right sulcal 
list attached to po6 and antl. A prominent, characteris- 
tic spine, the sulcal spine , occurs in the middle of this 
list at anterior corner of antapical plate. Anteriorly, 
this list is continuous with posterior girdle list. Poste- 
riorly it terminates at posterior end of ventral area. 
The anterior (epithecal) part of right sulcal list is at- 
tached to pr6 and as and is continuous posteriorly with 
distal end of anterior girdle list. 

Although the boundaries of most of plates are indi- 
cated by ridges placed at some distance from the edges, 
certain sutures are not so marked and extra ridges oc- 



FAMILY GONYAULACACEAE 



51 



cur on many plates. Thus any diagnosis of the plate pat- 
tern based on the pattern of ridges would be erroneous. 
Careful dissection is necessary to insure a correct plate 
formula. The third apical and the second anterior inter- 
calary are particularly difficult to demonstrate. The 
second apical bears two ridges removed from the edges; 
the first anterior intercalary has three (fig. 63A). 

The antapical spine is massive, solid, and conical, 
terminating the hypotheca and borne by the antapical 
plate. It is 4.1 (2.4-4.5) girdle widths long and from 1 
to 2 girdle widths in diameter at base. It is covered 
with the same fine areolation as that of the body and is 
marked with ridges running longitudinally. 

Variation . Gonyaulax fusiformis shows considera- 
ble variation in size and in length of antapical spine, but 
other characters are comparatively constant. Length of 
body varies from 67 to 98 microns; length of antapical 
spine from 12 to 23 microns or from 2.4 to 4.5 girdle 
widths. Body shape very constant except that width at 
girdle shows a tendency to vary; thej/d ratio varies 
from 1.68 to 1.98. Sometimes the "sulcal spine" is 
double, and one specimen was found without this spine. 
The surface markings show a high degree of constancy, 
being always a very delicate areolation with scattered 
large pores. The right sulcal list may end at sulcal 
spine or may continue beyond to antapical end of sulcus. 

Comparisons . Although the plate pattern of G. fusi - 
formis is fundamentally similar to that of G. pacifica , it 
differs somewhat from that of the latter species. Its ma- 
jor plate pattern is composed of the same number of 
plates as that in G. pacifica, but the arrangement of its 
plates differs from that in G. pacifica in some respects. 
Its first apical does not reach the girdle as it does in G. 
pacifica , but extends only to the anterior sulcal plate. 
Its third apical is much smaller, so that its second an- 
terior intercalary touches the first intercalary, which is 
not the case in G. p acifica . The apical process of ap3 is 
not represented in G. p acifica . 

In regard to the ventral area, the arrangement of the 
plates in G. fusiformis is rather similar to that in G. 
pacifica , but there is one less plate in the former spe- 
cies; the posterior accessory is lacking. In G. pacifica 
the intercalary plate is next to the largest of the sulcal 
complex, whereas in G. fusiformis it is the smallest. 
Its position, however, on the right of the sulcus just an- 
terior to the posterior plate and not touching the flagel- 
lar pore, is the same in the two forms. The extra sul- 
cal plate in G. p acifica, the posterior accessory, is pos- 
terior to the flagellar pore. Its anterior end forms the 
posterior end of the pore. It has probably been formed 
by the splitting off from its neighbor to the left, the left 
sulcal plate. Thus, the left and posterior accessory sul- 
cal plates in G. pacifica would be homologous with the 
left sulcal plate in G. fusiformis ; this latter plate has an 
arm extending along the left side of the pore to pol, 
probably homologous with the anterior part of the left 
sulcal plate in G. pacifica . 

Gonyaulax fusiformis shows some relationship to 
Spiraulax kofoidii and in some respects it is intermedi- 
ate between Spiraulax and Gonyaulax . It agrees with 
Spiraulax in that the second anterior intercalary plate 
touches the first (which in Spiraulax, however, is the 
third apical). It also agrees in the number of the sulcal 
plates, viz., six. The general arrangement of the sulcal 
plates in the two species is the same although there are 
two important differences in the details of the arrange- 
ment: First, in Spiraulax the left sulcal plate does not 



have an arm extending along the side of the flagellar 
pore, so that the entire left side of the pore is formed 
by the first postcingular plate; the left sulcal plate marks 
only the posterior edge of the pore. Secondly, the rela- 
tive sizes of the plates differ in such a way that in Spir - 
aulax the right sulcal plate has been squeezed out from 
contact with the pore, so that the right side of the pore 
is formed chiefly by the right accessory sulcal plate and 
to a small extent by the notch of the anterior plate. So 
far as the sulcus is concerned, it may be concluded that 
G. fusiformis is more closely related to G. p acifica than 
to Spiraulax . The agreement with Spiraulax in the num- 
ber of plates is outweighed by the difference in the pat- 
tern of the sulcal plates. Only the splitting of one plate 
in G. pacifica is sufficient to show good agreement with 
the sulcal plates of G. fusiformis, whereas considerable 
adjustment of plates surrounding the pore would be nec- 
essary to show agreement with Spiraulax . 

Differences in the epithecal plate pattern emphasize 
the distant relationship of these two forms. In Spiraulax 
the plate which is homologous with the first anterior in- 
tercalary in Gonyaulax fusiformis is an apical. Thus in 
Spiraulax there are four apicals and only one anterior 
intercalary, whereas in G. fusiformis there are only 
three apicals and two intercalates. In Spiraulax the 
first apical does not extend either to the girdle or to the 
anterior sulcal plate, but terminates at the anterior 
margin of the first precingular, so that the anterior in- 
tercalary extends over and touches the first precingular. 
Kofoid (1911b) stressed this point in creating the genus 
Spiraulax . The ventral epithecal pore so characteristic 
of the genus Gonyaulax is absent in Spiraulax . 

There is a superficial resemblance between G. fusi - 
formis and Spiraulax in general body shape, so that 
when a specimen of the former species is viewed under 
the low power of the microscope it may be confused with 
a species of Spiraulax . Under the high power, however, 
a glance at the surface of the plates is sufficient to dis- 
tinguish these two forms without any analysis of the plate 
pattern. Spiraulax is coarsely reticulate or with round- 
ed pits, without apparent pores. Gonyaulax fusiformis 
is very finely areolate with a few large pores scattered 
over the plates. The prominent sulcal spine will dis- 
tinguish this species from Spiraulax, although its ab- 
sence is not a positive identification of Spiraulax . 

Historical . It is possible that Murray andWhitting's 
Gonyaulax jolliffei (1899, p. 324, pi. 28, fig. la, b) was 
based on an aberrant specimen of G. fusiformis (see p. 
54). The plate pattern is so poorly figured by these 
authors that definite identification is not possible. The 
presence of a left sulcal spine and the general body 
shape suggest, however, that Murray and Whitting s form 
is not specifically identical with our material. For this 
reason and in order to avoid confusion in the literature, 
it was deemed advisable to give our species a new name 
and to retain the name Gonyaulax j olliffei for Murray 
and Whitting' s species. Kofoid s Spiraulax is separate 
from each of these (see p. 52). 

Gonyaulax fusiformis was figured by Favillard(1931, 
pi. 2, fig. 3) under the caption Gonyaulax blrostris Stein, 
Although the plate pattern is not indicated, this form is 
easily identifiable with the present species by its char- 
acteristic body shape and antapical spine. The specie* 
differs from G. blrostris Stein in body shape and plat* 
pattern. 

Distribution . Pavillard (1931) reported this spe- 
cies from the tropical Atlantic. 



52 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



In the Carnegie collection G. fusiformis was found 
at 19 stations: 2 in the Atlantic and 17 in the Pacific. 
There are 33 records of occurrence, all rare. The spe- 
cies occurred about equally at the three depths, with 12 
records for the surface, 12 for 50 meters, and 9 for 100 
meters. There are 21 pump records and 12 net records. 

The species was closely limited to the tropics. In 
the Atlantic it did not occur north of 30° north. In the 
Pacific it was not found north of 29° north or south of 
16° south. No center of abundance was indicated. The 
17 record stations in the Pacific were rather irregular- 
ly scattered and showed no correlation with geographic 
location or with dynamic conditions (fig. 61). 

The surface temperatures at the stations where the 
species occurred at any depth varied from 22° 7 to 
28°.7 C. The hydrographic conditions in situ were as 
follows: temperature, 18°7 to 28°7 C; salinity, 34.2 
to 37.0 o/oo; pH, 8.16 to 8.39; phosphate, 3 to 40 mg 
P0 4 /m 3 . 

This is obviously a rare tropical species restricted 
to warm water. It is remarkable that it was found more 
often in the nutrient-poor water. Of the 33 records of 
occurrence, all but 7 were in water with a phosphate 
content less than 10 mg P04/m 3 . Type locality: Car - 
negie station 18. 



Genus ACANTHOGONYAULAX (Kofoid) Graham 

Diagnosis . Body angular, with prominent lists and 
brush-formed hypothecal spines simulating Ceratocorys . 
Girdle premedian. Plate pattern: apical platelet, 3ap, 
9pr, 6g, 7s, 6po, lp, lant. Ventral epithecal pore on 
first apical plate. One species. Marine. 

Type species . Acanthogonyaulax spinifera (Murray 
and Whitting) Graham. 

Historical . Acanthogonyaulax was proposed as a 
subgenus of Gonyaulax by Kofoid (1910) to include Mur- 
ray and Whitting s (1899) Ceratocorys spinifera (see 
below, pp. 51-52). This subgenus is here raised to the 
rank of genus. 

Comparisons . Acanthogonyaulax has a superficial 
resemblance to Ceratocorys, particularly to C. horrida. 
The hypotheca of Acanthogonyaulax resembles that of C. 
horrida in the great development of antapical brush 
spines and in the intervening lists. The epitheca, on the 
other hand, is prolonged into a short tubular horn, 
whereas in Ceratocorys the epitheca is low dome-shaped. 

A more fundamental resemblance between these two 
genera is expressed by the similar number and pattern 
of the major hypothecal plates. There is a disparity in 
the size of some of these plates, however. 

The posterior intercalary is much more extensive, 
and the first postcingular is gomewhat larger in Acan - 
thogonyaulax than in Ceratocorys . The second postcin- 
gular, on the other hand, is a small ventral plate in 
Ceratocorys. whereas in Acanthogonyaulax it is large, 
equal in size to the postcingulars of the lateral and dor- 
sal sides. 

The epitheca of Acanthogonyaulax differs markedly 
from that of Ceratocorys, not only in shape but also in 
the number and the pattern of the plates. The number 
of precingular plates in Ceratocorys is five; in Acan - 
thogonyaulax it is nine. The major part of the epitheca 
in Ceratocorys is composed of four precingular plates, 
whereas in Acanthogonyaulax six of the precingular 
plates constitute most of the epitheca. The small first 



precingular plate in Ceratocorys is represented in 
Acanthogonyaulax by three minute precingular s. The 
apical region in Ceratocorys is composed of four plates: 
two apicals and two inter calaries; in Acanthogonyaulax 
there are three plates in this region, all apicals. 

A study of the sulcal complex of these two genera 
shows even less relationship between them than does a 
comparison of the epithecal plates. There are seven 
plates in the ventral area of Acanthogonyaulax , and only 
five in Ceratocorys . Acanthogonyaulax is unique in that 
the anterior sulcal plate is removed from the flagellar 
pore. In Ceratocorys the posterior part of the ventral 
area never flares out into a prominent part of the ven- 
tral aspect as it does in Ac anthogony aulax . This feature, 
on the other hand, is characteristic of Gonyaulax . 

Acanthogonyaulax is more closely related to Gon - 
yaulax than to Ceratocorys . The hypotheca has the same 
number of plates in the two genera, although the arrange- 
ment is somewhat different. In Gonyaulax the first post- 
cingular is much smaller and the posterior intercalary 
is much longer and narrower than in Acanthogonyaulax . 
The antapical plate in Gonyaulax is more restricted. 

It is more difficult to compare the epithecal and 
sulcal plates of Acanthogonyaulax with those of Gonyau - 
lax than with those of Ceratocorys because so little crit- 
ical work has been done on Gonyaulax . For that reason 
the present discussion is based on only two species of 
Gonyaulax ; G. pacifica and G. fusiformis . As stated 
above (p. 46), the present concept of the genus Gonyau - 
lax is probably too broad. 

The first apical plate in Acanthogonyaulax does not 
extend to the girdle or to the ventral area; in Gonyaulax 
it extends to the girdle. The number of precingular 
plates is six in Gonyaulax, nine in Acanthogonyaulax . 
The extra three precingulars in the latter genus are the 
three minute ventral ones, the first, second, and third. 
It is possible that the first two represent the anterior 
part of the anterior sulcal plate of Gonyaulax," in which 
case the anterior part not only has separated from the 
posterior part but also has split longitudinally. The 
third precingular could, then, represent the lower part 
of the first antapical of Gonyaulax . There is much great- 
er difficulty in homologizing the sulcal plates proper of 
these two genera, in spite of the fact that the total num- 
ber of plates may be the same. The flagellar pore does 
not bear the same relation to the various plates in the 
two genera (see fig. 1). In Acanthogonyaulax the anteri- 
or sulcal plate is removed from the pore, whereas in 
Gonyaulax it forms its anterior edge. In Acanthogonyau - 
lax the pore is bordered by four plates, two anterior, 
two posterior; in Gonyaulax it is bounded by five plates, 
only one of which is anterior, one is posterior, the rest 
lateral. The greatest resemblance in these areas seems 
to be that the posterior plate in each case is the largest. 
Their differ ence in shape, however, is extreme. In 
Gonyaulax it is subelliptical; in Acanthogonyaulax , sub- 
triangular with two widespread limbs. 

On the basis of the differences in the epithecal and 
sulcal plate patterns, we are forced to conclude that 
Acanthogonyaulax is only remotely related to the species 
of Gonyaulax included in this report. If further investi- 
gations show that other species, now allocated to Gon - 
yaulax , are similar in pattern to G. pacifica and G. fusi - 
formis , then we may conclude that Acanthogonyaulax 
and Gonyaulax not only are distinct genera but are sep- 
arated by a divergent evolutionary development of con- 
siderable extent. 



FAMILY GONYAULACACEAE 



53 



Acanthogonyaulax spinifera 

(Murray and Whitting) Graham 

(Figures 64, 65) 

Ceratocorys spinife ra Murray and Whitting, 1899, p. 

329, pi. 30, fig.~l>a, b, e (not fig. 6c, d). 
Gonyaulax ceratocoroides Kofoid, 1910, p. 182. Kofoid, 

1911a, pp. 202, 247. Pavillard, 1931. p. 50, pi. 2, 

fig. 2. 

Dimensions . Length (h), measured in ventral view 
from apex to posterior end of sulcus, 63 (55-75) mi- 
crons. Diameter (d) 49.5 (42-58) microns. Length of 
ventral spines 23 (5-31) microns, or about 5 girdle 
widths for the average. Girdle width 4-5 microns. 
Thirteen specimens were measured. 

Shape . Strongly resembles Ceratocorys in general 
appearance because of angularity of body and prominent 
brushlike spines on hypotheca (figs. 64B and 65). Body, 
including apical horn, somewhat longer than broad. The 
h/d ratio is 1.27 (1.19-1.44). Body nearly circular in 
girdle region (fig. 64C, E) but hypotheca very angular 
posteriorly (fig. 64B, C). Epitheca rather low but ex- 
tended as a tubular horn along its distal quarter. Be- 
sides the constriction formed by the base of this horn, 
there is another constriction halfway to girdle, promi- 
nent only on the right side. Thus, there are two shoul- 
ders on epitheca which are most distinct on the right 
side of body (fig. 64B). Hypotheca squarish in outline, 
sometimes with a constriction in the middle, at least ol 
one side, usually the right (fig. 64B); truncated posteri- 
orly. Antapex squarish and sunken in center (fig. 64B, 
C). A bulge occurs on hypotheca at base of each ven- 
tral spine. Girdle sinistral, displaced about 3 girdle 
widths, not excavated; no overhang. 

Ventral area narrow anteriorly but flares out pos- 
teriorly to full width of antapex into a bilobed area. 
Sulcus a deep, narrow groove occupying entire anterior 
half of ventral area and obscured by various lists asso- 
ciated with it (figs. 64B, 65). Flagellar pore occurs op- 
posite distal end of girdle; almost hidden by overhang 
of postcingular and right sulcal plates. 

Plate pattern . The three apical plates are of une- 
qual size. The first is narrow and ventral, and extends 
only about two-thirds of way to girdle. It bears the ven- 
tral epithecal pore. The second and third apicals, only 
half as long as the first, are broad and compose most 
of apical horn (fig. 64B, E). Apical closing platelet 
present. Anterior intercalary plates absent. Of the 
nine precingular plates, the first three are minute 
plates just anterior to ventral area. The other six are 
subequal in size and comprise the larger part of epithe- 
ca (fig. 64E). The six girdle plates subequal in size. 
(Girdle sutures indicated by arrows in fig. 64E.) First 
postcingular is a small narrow plate overhanging sulcus 
as in Gonyaulax (fig. 64A, B). The other five postcingu- 
lars large and subequal in size (fig. 64C). The posteri- 
or intercalary plate lies between left side of ventral 
area, the second and third postcingulars, and the antap- 
ical plate. The antapical plate is large and squarish, 
constituting the truncated antapex. Its four long sides 
border the third to fifth postcingulars and the posterior 
sulcal plate, but it also has two relatively short sides 
bordering the posterior intercalary and the sixth post- 
cingular plates (fig. 64C). 

Ventral area composed of seven plates. The poste- 
rior sulcal plate is the only large one and forms a ma- 
jor part of the ventral aspect of hypotheca (fig. 64A, D). 



Other sulcal plates minute. The anterior sulcal plate is 
opposite the proximal end of girdle. It has no anterior 
projection into epitheca. Posterior to this plate and just 
anterior to flagellar pore are the right accessory and 
left accessory sulcal plates. Between flagellar pore anc 
posterior sulcal plate are three plates: on the left side 
of left sulcal plate; on the right side, the right sulcal 
plate; adjacent to the pore and between the last plate and 
the posterior sulcal plate there is an intercalary sulcal 
plate (fig. 64A, D). Right sulcal plate overhangs pore in 
such a way that it is ventral to left sulcal plate (fig. 65). 

Thecal wall . Surface of larger body plates covered 
with deep pits regularly spaced. Pores not demonstrat- 
ed in these pits. Second and third precingular plates, 
but not the first, with pores. Girdle plates with two 
rows of pores. Ventral epithecal pore occurs on right 
edge of first apical plate. 

Lists and spines . Lists and spines reach a high de- 
velopment in this species. Girdle lists are usually a- 
bout 3 girdle widths wide, strengthened by heavy ribs 
which are connected to numerous heavy listlike cross 
ribs on girdle plates (figs. 64C, E, 65). Strong lists bor- 
der all margins of ventral area. Right sulcal list at- 
tached to sixth postcingular plate. Left sulcal list at- 
tached to first postcingular and posterior intercalary. 
These two lists extend onto ventral antapical spines. 
Anterior (epithecal) right sulcal list attached to ninth 
precingular plate. It borders right margin of epithecal 
part of ventral area between girdle ends and extends 
somewhat beyond, anteriorly. Body lists well developed 
along all sutures of hypotheca and along all sutures of 
larger precingular plates. Apical plates, however, sin- 
gularly free of lists (figs. 64B, E, 65). All body lists 
extending to girdle run out to edge of girdle lists. The 
body lists often strengthened by irregularly scattered 
ribs, usually extending out from base of list. 

Long spines with "brushes" are a prominent fea- 
ture of this species. These spines are formed at cer- 
tain junctions of body lists. The two most prominent 
spines are at the ventral corners of antapical plate; two 
other antapical spines occur at the dorsal corners of 
this plate. The fifth spine is left lateral in position, be- 
ing located at left corner of the posterior intercalary. 
The "brushes" consist of secondary thickenings running 
out from the primary thickening which composes the 
body of this spine at the list junction. 

Variation . Size and shape of body fairly constant. 
The greatest variation occurs in the lists and spines. 
The variations may represent growth stages. Length of 
ventral spines, however, constant: from 20 to 31 mi- 
crons except for one specimen with spines 5 microns 
long. Displacement of girdle varies more than in most 
species of Peridiniales; a continuous series with dis- 
placements from 1.5 to 4 girdle widths was found. 

All our specimens had five spines, although in one 
case one spine was double. Murray and Whitting (1899) 
stated that the usual number of spines is six and that 
they found one specimen with only two. Whether the 
former value should be accepted may be considered 
doubtful. Since the spines are developed at the junction 
of lists, however, a maximum number of seven seems 
possible. The spines may be straight or curved. Cur- 
vatures are particularly evident in Murray and Whit- 
ting's figures. Outer margins of lists may be straight 
or very much indented in parts between spines or be- 
tween spines and girdle list. 

Historical . Murray and Whitting (1899) described 



54 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



and tigured this species under the name Ceratocorys 
spinifera . They not only erred in the generic allocation, 
however, but they also confused the species with two 
other species of Ceratocorys (Kofoid, 1910). Kofoid 
(1910) realized the affinity of this species to the genus 
Gonyaulax and placed it in this genus in his revision of 
the genus Ceratocorys . No figures were given in this 
report. Later, Kofoid (1911a) emphasized the differ- 
ences between this and the other species of Gonyaulax 
by placing it in a new subgenus, Acanthogonyaulax . 
Since the specific name spinifera was preoccupied in 
Gonyaulax , Kofoid proposed the new name ceratocoroides . 
Kofoid (1911a, p. 202) described Acanthogonyaulax as 
having six plates in the apical region instead of three. 
He probably based his judgment on the drawings of 
Murray and Whitting, in which the plate pattern of this 
region is very obscure. 

On the basis of a detailed study of the skeletal anat- 
omy of this species and of all the species of Ceratocorys . 
as well as of two representatives of the genus Gonyau - 
lax, Acanthogonyaulax is here raised to the rank of an 
independent genus, related both to Ceratocorys and to 
Gonyaulax but separated from these genera by wide ev- 
olutionary gaps. Since Murray and Whitting's specific 
name spinifera is not preoccupied in Acanthogonyaula x, 
it has priority and must be reinstated. 

Distribution . Acanthogonyaulax spinifera is an ex- 
tremely rare tropical species. Murray and Whitting's 
(1899) original material was from the Atlantic. Pavil- 
lard (1931) found this species at one station off Spain in 
1905. Apparently these are the only records of its oc- 
currence up to the present investigations. 

In the Carnegie collections the species was not 
found in the Atlantic, but was collected at 22 stations in 
the Pacific. These stations are widely distributed over 
the tropical Pacific, grouped in the following manner: 
in the North Pacific, 5 stations northeast of the Hawai- 
ian Islands, 7 stations in the North Equatorial Current 
north of the Marshall Islands, and 3 stations between 
Guam and Tokyo; in the South Pacific, 2 stations east of 
the Samoan Islands, and 5 stations between the Galapa- 
gos and Easter Islands (fig. 61). There are 32 records 
of occurrence: 30 rare and 2 occasional. The species 
was found about equally at the 3 levels, with 10 records 
for the surface, 12 for 5p meters, and 10 for 100 me- 
ters. There are 24 net records and 8 pump records. 

This tropical species reached its greatest distance 
from the equator in the western Pacific, where it oc- 
curred almost to 35° north (station 113). In the eastern 
Pacific it was found only to 33° north (station 145). In 
the South Pacific it was not found south of 19° south. 
The 2 records of "occasional" were in the North Equa- 
torial Current (stations 100 and 101). 

The surface temperatures at the stations where the 
species occurred at any depth varied from 22°.4 to 
28° 5 C. The ranges of hydrographic conditions in situ 
were as follows: temperature, 16°0 to 28°6 C; salinity, 
34.1 to 36.3 o/oo; pH, 8.16 to 8.39; phosphate, 3 to 40 
nag P04/m 3 . 

It may be concluded from the Carnegie observations 
that A. s pinifera is a very rare but widely distributed 
tropical species, seldom collected because of its sparse 
numbers. Water of low nutrient content is no barrier 
to it, as 18 of the 32 records were from water with less 
than 10 mg PO^m 3 . 



Genus SPIRAULAX Kofoid 

Diagnosis . Plate formula: 4ap, la, 6pr, 6g, 6s, 
6po, Ip, lant. First apical does not touch girdle or an- 
terior extension of ventral area. Posterior intercalary 
wide. Sulcal plates: as, ra, rs, Is, i, ps. Ventral epi- 
thecal pore absent. 

Comparisons . Spiraulax is closely related to Gon - 
yaulax . It has the same number of plates in all regions 
of the theca, but the arrangement of the plates in the two 
genera is significantly different. In Spiraulax there are 
four apicals and only one anterior intercalary. In Gon - 
yaulax pacifica and G. fusiformis there are only three 
apicals, but there are two, instead of one, intercalates. 
The intercalary in Spiraulax is probably homologous 
with a2 in Gonyaulax, whereas al of Gonyaulax is prob- 
ably homologous with the third apical in Spiraulax . In 
Gonyaulax the first apical extends either entirely to the 
girdle or to the anterior end of the ventral area; in 
Spiraulax this plate lies at the anterior edge of first pre- 
cingular. The apical limb of ap2 and the ventral epithe- 
cal pore found in Gonyaulax are absent in Spiraulax . 

The hypothecal plate patterns are the same in the 
two genera, although pi is usually narrower in Gonyau - 
lax . The ventral area of Spiraulax is similar to that of 
G. fusiformis , but G. pacifica has one more sulcal plate. 

Spiraulax is less closely related to Acanthogonyau - 
lax than to Gonyaulax . Acanthogonyaulax has nine, in- 
stead of six, precingulars; it has no anterior intercala- 
ries; the first apical does not extend to the girdle; and 
the ventral area is unique (see pp. 5-6). 

Remarks . The Carnegie material is similar to 
that described and figured by Kofoid (1911b) from the 
San Diego region. Our diagnosis of the pattern of the 
major body plates agrees with that of Kofoid. The pat- 
tern of the ventral area has not been reported before. 

Kofoid (1911b) identified his material with that of 
Murray and Whitting (1899) published under the name 
Gonyaulax j olliffei . He considered this species to be 
generically distinct from Gonyaulax and established the 
new genus Spiraulax to include the one species. In our 
opinion, Kofoid was justified in doing this for his own 
material, which is specifically the same as ours. Gon - 
yaulax j olliffei Murray and Whitting, however, is prob- 
ably more closely related to G. fusiformis n.sp. than to 
Spiraulax (see above). Since it is impossible to deter- 
mine the plate pattern in this species without dissection, 
the figures given by Murray and Whitting (1899, pi. 28, 
fig. la, b) probably do not show the correct plate pat- 
tern, as these authors apparently did not dissect their 
specimens. The shape of the body of their species is 
not that of Spiraulax . Although the first apical is shown 
not reaching the ventral area or girdle, on the other 
hand, the accompaniment of this condition in Spiraulax, 
i.e., the intercalary touching the first precingular, is 
not shown. In fact, no intercalary plates are shown at 
all. The ventral epithecal pore and slender first apical 
are not shown, but these are very easily overlooked in 
undissected specimens. In G. fusiformis the presence 
of the slender first apical would never be suspected 
without dissection. 



FAMILY GONYAULACACEAE 



55 



Spiraulax kofoidii new name 
(Figure 66) 

Spiraulax j olliffei Kofoid, 1911b. pp. 296-298, pi. 19, 
figs. 1-5. Forti, 1922, p. 82, pi. 6, fig. 71. not 
Gonyaulax j olliffei Murray and Whitting, 1899, p. 
324, pi. 28, fig. la, b. 

Dimensions . Length of body (l), excluding antapi- 
cal spine, 123 (101-160) microns. Diameter at girdle 
(d) 79 (71-105) microns. Length of antapical spine 10 
(0-18) microns. Width of girdle 5 to 6 microns. Twenty- 
nine specimens were measured. 

Shape . Body broadly fusiform. The _l/d ratio is 
1.54 (1.40-1.77). Epitheca prolonged as an apical horn 
extending 0.75 transdiameter from proximal end of gir- 
dle. Hypotheca also extends as a horn but is shorter 
than epitheca; length 0.46 transdiameter, measured 
from distal end of girdle. Antapical horn terminates in 
a stout spine about 2.5 girdle widths long; in strongly 
sculptured specimens sometimes so heavy that it ap- 
pears as a continuation of the body proper. Kofoid' s 
(1911b, pi. 19) specimen does not show the spine al- 
though he indicates it in his diagnosis. In ventral view 
(fig. 66G) epitheca usually somewhat concave on left side 
but with prominent hump on right side, although Kofoid' s 
figure does not show much convexity on right side. Hy- 
potheca has concavity on right side with hump on left 
side. In apical view body almost circular except for 
indentation at sulcus, where girdle is depressed about 
2 girdle widths (fig. 66D, E). Girdle approximately 
equatorial, sinistral, displaced from 3 to 4 girdle 
widths; deep excavation obscured by heavy sculpturing; 
no overhang. 

Ventral area elongate, slightly sigmoid, narrow in 
middle but expanded at both ends (fig. 66 A, G). It ex- 
tends into epitheca about 2.5 girdle widths. Between 
girdle ends it is extremely narrow but posteriorly it 
flares out into an elliptical flat area almost 2.5 girdle 
widths wide, then narrows somewhat to antapex. Flagel- 
lar pore narrow, elongate, extending from posterior 
margin of proximal end of girdle to anterior margin of 
distal end. 

Plate pattern . First and fourth apicals ventral; 
comparatively small. Second and third apicals large 
and dorsal (fig. 66C, E, G). 

Apical plates separate easily and preserved speci- 
mens are usually found with apicals parted. No apical 
platelet found in our material, but this may be due to its 
ready loss during the parting of the apicals. First api- 
cal does not extend to girdle but terminates at anterior 
edge of prl. Anterior intercalary large, lying between 
ap4 and pr6 and part of pr5. First precingular large, 
extending a quarter of the way around left side of body. 
Other precingulars subequal in size, the third and 
fourth being the smallest. 

The six girdle plates subequal in length except the 
sixth, which is much longer than the rest. Positions of 
sutures between girdle plates indicated by arrows in 
figure 66E. The six postcingulars subequal in size ex- 
cept the first, which is small and borders flagellar pore. 
Posterior intercalary is broad, lies between pol to po3, 
and antl, and borders middle third of left edge of ven- 
tral area. Antapical plate large, forming distal part of 
conical antapical horn. Posterior part of ventral area 
set into its ventral face. 

Ventral area composed of six plates: a large pos- 
terior plate, a medium-sized anterior plate, and four 



small intermediate plates (fig. 66A, B). Anterior plate 
forms anterior margin of flagellar pore and extends into 
epitheca almost halfway up side of anterior intercalary, 
where it ends in a point. It has an arm which extends 
posteriorly along anterior part of left edge of the pore. 
The rest of right edge of the pore is formed by right ac- 
cessory sulcal plate; the right sulcal plate barely touch- 
es the pore. Left sulcal plate forms only posterior edge 
of pore. Left edge of pore formed by first postcingular 
plate. Intercalary sulcal plate lies between posterior 
and right sulcal plates. The posterior sulcal plate 
forms a large elliptical area on hypotheca. Most of the 
sulcal plates are rotated on their long axes or are dis- 
torted in the formation of the deep sulcus so that their 
broadest aspects are not seen in ventral view. Figure 
66B shows the sulcal plates in their broadest aspects. 

Thecal wall. All our specimens are thick-walled, 
but Kofoid (1911b) found thin-walled individuals. Body 
of thinner individuals covered with a definite reticula- 
tion with rounded meshes; but in heavier specimens, 
this type of differentiation gives way to a very thick wall 
with fairly regularly spaced pits. Kofoid states that 
these pits have minute pores in the bottom, but these 
were not detected among the Carnegie specimens under 
the oil immersion objective. Ventral epithecal pore ab- 
sent. Surface sculpturing weak or lacking along plate 
sutures; sometimes there is here a zone of smooth the- 
cal wall more than a girdle width wide. Ridges or lists 
along body sutures absent except at dorsal sutures of 
apical plates, where very small lists occur. Girdle 
plates with two rows of polygons or pits. Posterior sul- 
cal plate reticulate or pitted. Pits and pores occur on 
anterior and intercalary sulcal plates. Left and right 
sulcal plates bear only pores; right accessory sulcal 
plate is entirely smooth. 

The anterior part of the first apical plate is bent 
into a U-shaped trough with concavity facing inward (fig. 
66E). In this manner the apex is formed almost entirely 
by the first apical alone. When a specimen is viewed 
ventrally, the sides of this trough appear as two dark 
lines, so that the area between is light by contrast. 
Kofoid interpreted this as a notch extending from the 
apex and covered by a thin membrane, and suggested 
its similarity to a structure in the first apical of Peri- 
dinium . This is, however, an optical illusion which can 
be dispelled by examining the separated apical plate in 
apical view. The structure in Peridinium, moreover, 
is quite different from this. In that genus there is a dis- 
tinct linear plate, the ventral apical platelet, which lies 
between the apex and the anterior end of the first apical 
plate (see p. 16). 

All sutures, including those of girdle and ventral 
area, formed as rabbet joints with underlapping mem- 
branes as in Peridinium (see p. 10). The membranes 
of the girdle plates do not underlap the body plates, but 
lie against the cingular lists, which are attached to the 
body plates (m, fig. 66F). Striated intercalary zones 
were not found. 

Lists. Girdle lists about 1 girdle width wide; very 
thick in thick-walled individuals, so that it is difficult 
to distinguish them from body wall. In thinner individ- 
uals, lists are strengthened by regularly spaced, stout 
spines running out from body wall almost to edge of 
lists. In heavier individuals, these spines may be 
branched or form a reticulation. Sulcal lists well de- 
veloped. Right anterior sulcal list occurs along left 
edge of precingular 6 and joins anterior girdle list. Left 



56 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



and right posterior sulcal lists 2 girdle widths wide. 
They do not extend to posterior end of ventral area, but 
end about halfway down posterior sulcal plate (fig. 66G). 
Sulcal lists quite evident in lateral view (fig. 66D). 
Right sulcal list is attached to po6; the left is in two 
parts, attached posteriorly to p and anteriorly to pol. 
The portion of the ventral area which is free of lists 
(the posterior part) is limited to the region bordered by 
the antapical plate. Left list usually without structural 
differentiation, but the right has short ribs or reticula- 
tions at its base. Antapical spine thick, solid, irregu- 
larly furrowed, about 2.5 girdle widths long. 

Historical . This species was first reported by 
Kofoid (1911b), who identified his material with Gonyau - 
lax j olliffei Murray and Whitting (1899) and assigned it 
to the new genus Spiraulax . Since, in our opinion, Mur- 
ray and Whitting's specimens do not belong to Spiraulax 
(see p. 52), we are here assigning a new name to Ko- 
foid's species, Spiraulax kofoidii new name. 

Distribution . The references of Schroder (1900) 
and Karsten (1907) to Gonyaulax j olliffei Murray and 
Whitting for the Mediterranean and Indian oceans, re- 
spectively, should not be accepted, since the figures of 
Murray and Whitting have not yet been positively identi- 
fied. The records of Spiraulax j olliffei Kofoid of Pavil- 
lard (1931) and of Matzenauer (1933), however, probably 
refer to the present species. Pavillard found it in the 
Atlantic and Mediterranean; Matzenauer in the Indian 
Ocean. Forti's (1922) records for the Mediterranean 
are not substantiated by drawings as his drawings are 
copies. 

In the Carnegie collections Spiraulax kofoidii was 
found at most of the tropical stations. It occurred at 
80 stations: 12 in the Atlantic and 68 in the Pacific. 
There are 162 records of occurrence, with 119 rare, 39 
occasional, and 4 common. The species was found less 
commonly with increase in depth, with 66 records for 
the surface, 51 for 50 meters, and 45 for 100 meters. 
There are 39 pump records and 123 net records. The 
species was found in both hemispheres and in all months 
of the year, except June and July. 

The species is widely distributed over tropical and 
subtropical stations, although the records are not contin- 
uous. In the Atlantic it occurred in the Gulf Stream as 
far north as 38° north (station 1, surface temperature 
24° C). Otherwise it was not found north of 24° north in 
that ocean (station 19, surface temperature 27° C). In 
the Pacific it was found only to 26° north in the west 
(station 110, surface temperature 24° C) but to 37° 
north in the east (station 130, off California, surface 
temperature 16°.2 C). In the South Pacific it did not oc- 
cur farther south than 35° south (station 62, surface 
temperature 19° C). It was most abundant north of 
Easter Island and in the line of stations east and north 
of the Samoan Islands. 

The surface temperatures at the stations where it 
occurred at any depth varied from 19° to 29°.3 C, ex- 
cept for the one record off California (station 130), 
where the temperature was 16°2. The hydrographic 
conditions in situ were as follows: temperature, 13°.l 
to 29°.2 C; salinity, 33.4 to 37.1 o/oo; pH, 7.80 to 8.47; 
phosphate, 2 to 178 mg PO^/m 3 . 

The species is probably indigenous to the areas with 
water of low nutrient content as well as to richer tropi- 
cal waters, as there are 59 records in water containing 
less than 10 mg PO4/111 3 . 



Family CERATIACEAE Lindemann 
Diagnosis. See Lindemann, 1928, p. 91. 
Genus CERATIUM Schrank 

Diagnosis . See Lindemann, 1928, p. 92. 

Remarks . Although the genus Ceratium is one of 
the commonest and most widespread of the peridinians 
and is usually the first genus to be reported from ex- 
pedition collections, its thecal morphology is still as 
poorly known as that of the rarer genera. In order to 
contribute something toward the knowledge of the mor- 
phology of the genus and to endeavor to find something 
which might throw light on the relationships of Cerati - 
um to other genera, C. payillardii was selected for 
study and subjected to a morphological analysis. 

That this analysis was not so successful as in the 
case of the other genera is not discouraging. Sufficient 
knowledge was gained to indicate that such studies with- 
in this interesting genus may be quite helpful in solving 
some of the systematic problems and in arriving at a 
proper understanding of relationships. 

Ceratium arcticum was also dissected, but in this 
species no trace of the ventral area had been preserved, 
so that only the grosser features could be determined. 
For this reason it is not reported here except as re- 
ferred to under "Comparisons" under C. payillardii . 



Ceratium pavillardii Jorgensen 
(Figure 67) 

Ceratium payillardii Jorgensen, 1911a, p. 74, figs. 157A, 
B7T38. JSrgensen, 1920, p. 92, fig. 83. 

Ceratium yultur Pavillard, 1905, p. 54, pi. 1, fig. 2. 

Ceratium tripos var. macroceras f. undulata Schroder, 
1900, pi. 1, fig. 17m [not fig. 17K, L]. 

Diagnosis . Diameter (d) 78 (60-90) microns. Api- 
cal horn more or less straight. Base of right antapical 
horn extends laterally from body. Base of left antapical 
horn bent abruptly anteriorly; sometimes there is a 
short posterior extension before the turn. Otherwise no 
posterior extension of antapicals. Antapical horns ex- 
tend laterally to anteriorly. 

Plate pattern . First apical with long margin on 
ventral area; fourth apical with very short margin on 
area. 

Girdle plates four. The functional girdle probably 
includes only the first three of these. First and fourth 
girdle plates short, ventral; second and third long, dor- 
sal. Suture gl/g2 in line with sutures prl/pr2 and 
pol/po2. First and second plates regular in outline. 
Third plate with distal end hammer-shaped (fig. 67D, F), 
probably marking end of girdle proper, as girdle lists 
end at this point. Fourth girdle plate peculiarly modi- 
fied at its distal end to form the concave roof of the 
horn trough (fig. 67E, G). 

Fifth postcingular, which forms ventral half of 
right antapical horn, is molded at its proximal end to 
form the horn trough (fig. 67G). In chains this trough 
encloses anterior part of apical horn of adjacent spec- 
imen immediately posterior. It is found in all speci- 
mens, since all specimens form at least temporary 
chains at division. 

Ventral area composed of a number of extremely 






FAMILY CERATIACEAE 



57 



thin, hyaline plates. Most of area anterior to girdle 
covered by one large plate, the largest of the area (fig. 
671). This plate is bordered along most of its margin 
with a line of closely spaced minute tubercles. The rest 
of the plate is covered with fairly regularly spaced tu- 
bercles of larger size. At left side of this plate there 
is a long, narrow, smooth plate. Ventral area posterior 
to girdle composed for the most part of two smooth 
plates. On the right side these are shorter than the an- 
terior plate because of the projection of the horn trough 
into the ventral area. The above four plates were each 
dissected from the others, so that their occurrence as 
distinct integral parts is well established. They include 
all the plates of the right side of the ventral area. 
There are other plates, however, on the left side. The 
number and position of these as well as the exact loca- 
tion of the flagellar pore or sulcus could not be deter- 
mined. The plates in this region are extremely mem- 
branaceous and nothing regarding their true shape or 
orientation could be ascertained. 

Comparisons . Our analysis of the ventral area of 
C. pavillardii agrees in part with that of Entz (1927) for 
a number of fresh-water species. Entz also found that 
most of the area is made up of three large plates. In 
his species, however, the shapes and relative sizes of 
these plates varied considerably in different species. 
It is probable, however, that the presence of these three 
plates is characteristic of all species of Ceratium , both 
fresh- water and marine. 

In regard to the other features of the ventral area, 
no analysis has been completely satisfactory. Entz 
shows for most species two small plates at the left side 
of the area alongside the longitudinal furrow. The na- 
ture of this furrow or the position of the flagellar pore, 
however, must still be considered uncertain. 

Entz's analysis of the right side of the ventral area 
and distal end of girdle is also unsatisfactory, so that no 
direct comparison can be made with our analysis of that 
region in C. pavillardii . 

Our own analysis of C . arcticum indicates that there 
is probably considerable variation among the species in 
respect to this region, so that the condition of C. pavil - 
lardii cannot be considered representative of the entire 
genus. In C. arcticum the fourth girdle plate is molded 
into a cap for the horn trough as in C. pavillardii, but 



the shape of the distal end of the third girdle plate is 
regular, not hammer-shaped. Furthermore, there is a 
continuation of girdle lists, or at least ridges, to the 
ventral area, so that the distal end of the girdle proper 
may be said to extend entirely to the ventral area, in 
marked contrast with the condition in C. pavillardii . 

Chain formation . Ceratium pavillardii is often 
found in chains of several individuals. For this reason 
the structure of the end of the apical horn and the horn 
trough of the body is of particular interest. The end of 
the apical horn is covered by a small platelet, the api- 
cal platelet. It is pierced in the center by a large pore. 
In chain specimens (except in the anterior ceil) this 
platelet, along with the ends of the apical plates, is very 
much thickened and convoluted, so that a knobby process 
is formed which holds the end of the horn fast in the 
socket of the top of the horn trough of the anterior spec- 
imen. This socket in the anterior specimen is formed 
mostly by the fourth girdle plate. Specimens not in 
chains have neither the knobby apical horn nor the deep 
socket at the end of the horn trough. Specimens in 
chains, with the exception of the apical cell, have much 
shorter apical horns. Perhaps a time factor operates 
here. It is suggested that, after division, if the ceils 
separate immediately, there is a growth at the end of 
the apical horn which results in an increase in the length 
of the horn, whereas, if the specimens remain connected 
for a short length of time, this growth results, not in 
increase in the length of the horn, but in formation of a 
knob at the end of the horn which acts to fasten the two 
cells together so that by the time cell growth is com- 
pleted the two cells are firmly secured to each other. 
Chain formation, on this basis, then, would depend on 
the formation of the knob during a short critical period 
while the mother cell undergoes division. 

Distribution . The genus Ceratium is distributed 
over all the oceans of the world and is one of the most 
valuable genera of the peridinians for distributional 
studies. Not only are there cold- and warm-water spe- 
cies, but many species show minor phenotypic variations 
which are useful in tracing dynamic conditions. 

The discussion of the distribution of all the species 
of Ceratium of the Carnegie collection constitutes an- 
other report. Since the distribution of C. pavillardii is 
included in that work, it is not reported here. 



TABLES 3-23 

TABLES OF DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 
(For tables 1 and 2 see page 7) 



Abbreviations and Numerical Equivalents used in Tables 

For Relative Abundance 
a (abundant) indicates over 50 individuals oc (occasional) from 11 to 25 individuals 

c (common) from 25 to 50 individuals r (rare) from 6 to 10 individuals 

For Apparatus 
n = sample taken by net p = sample taken by pump 

Values enclosed in parentheses and marked by asterisk ( )* are interpolated 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



61 



Table 3. Distributional and environmental records for Peridinium depressum Bailey 



Station 


Sample 


Depth 

(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

(°C) 


Salinity 
(o/oo) 


PH 


p 04 , 

mg/m3 










Atl 


antic 










3 


19 


100 


oc 


n 


5/21/28 


13.65 


35.89 


8.10 


48 


6 


37 


100 


r 


n 


5/31/28 


11.30 


35.55 


8.08 


40 


6b 


45 





c 


n 


6/ 2/28 


(12.44) 
(12.44) 


(35.55) (8.15) 
(35.55) (8.15) 


(21) a 




46 





oc 


n 


6/ 2/28 


6e 


52 





r 


n 


7/ 8/28 










6f 


53 





r 


n 


7/ 9/28 










6g 


54 





oc 


n 


7/10/28 










7 


56 





r 


n 


7/13/28 


8.92 


35.21 


8.08 


34 




57 


50 


a 


n 


7/13/28 


8.16 


35.25 


8.03 


47 




58 


100 


a 


n 


7/13/28 


8.12 


35.24 


8.04 


57 


10 


68 





oc 


n 


7/30/28 


10.94 


34.95 


8.08 


28 




69 


50 


oc 


n 


7/30/28 


9.86 


34.94 


8.04 


34 




70 


100 


oc 


n 


7/30/28 


6.56 


35.02 


7.95 


52 


11 


73 





oc 


n 


8/ 1/28 


10.67 


34.91 


8.06 


27 




75 





oc 


p 


8/ 1/28 


10.67 


34.91 


8.06 


27 h 


11a 


78 





oc 


n 


8/ 2/28 


(10.67) 


(34.91) 


(8.06) 


(27) b 


12 


79 





oc 


n 


8/ 5/28 


8.44 


33.65 


8.10 


27 




80 


50 


c 


n 


8/ 5/28 


3.95 


34.74 


7.96 


78 




81 


100 


c 


n 


8/ 5/28 


3.46 


34.87 


7.91 


95 




82 





c 


p 


8/ 5/28 


8.44 


33.65 


8.10 


27 


13 


83 





r 


n 


8/ 7/28 


11.27 


32.68 


8.09 


19 




85 


50 


a 


n 


8/ 7/28 


-1.64 


33.40 


7.87 


59 




86 


100 


a 


n 


8/ 7/28 


-1.10 


33.62 


7.87 


63 




87 





oc 


p 


8/ 7/28 


11.27 


32.68 


8.09 


19 


14 


91 


100 


r 


p 


8/ 9/28 


14.02 


35.59 


8.06 


34 




94 


100 


oc 


n 


8/ 9/28 


14.02 


35.59 


8.06 


34 




95 


50 


oc 


n 


8/ 9/28 


14.95 


35.10 


8.18 


16 


15 


97 





r 


P 


8/11/28 


24.81 


36.39 


8.21 


11 




101 


50 


r 


n 


8/11/28 


20.00 


36.48 


8.21 


8 




102 


100 


oc 


n 


8/11/28 


18.50 


36.45 


8.19 


15 


16 


107 


50 


r 


n 


8/13/28 


23.64 


36.41 


8.23 


8 




108 


100 


oc 


n 


8/13/28 


19.62 


36.48 


8.17 


13 


18 


118 


50 


r 


n 


8/17/28 


22.12 


36.82 


8.24 


5 


19 


123 


50 


oc 


n 


8/20/28 


25.31 


37.15 


8.27 


5 


20 


129 


50 


r 


n 


8/22/28 


25.72 


36.60 


8.26 


3 




130 


100 


r 


n 


8/22/28 


22.56 


36.73 


8.19 


5 


21 


137 


100 


r 


n 


8/24/28 


20.93 


36.75 


8.20 


7 


22 


144 


100 


r 


n 


8/27/28 


17.50 


36.10 


7.99 


123 


24 


153 


100 


r 


p 


8/31/28 


15.6 


35.6 


7.96 


99 




155 


50 


r 


n 


8/31/28 


23.1 


36.0 


8.14 


8 


25 


162 


100 


r 


n 


9/ 3/28 


14.6 


35.7 


7.93 


121 


28 


177 


50 


r 


n 


9/11/28 


26.7 


36.3 


8.26 


4 










Pacific 










111 


668 





oc 


n 


6/ 3/29 


20.1 


34.5 


8.18 


5 




671 





oc 


p 


6/ 3/29 


20.1 • 


34.5 


8.18 


5 


112 


675 


50 


r 


n 


6/ 5/29 


21.7 


34.6 


8.23 


7 


113 


680 





oc 


n 


6/25/29 


24.2 


34.5 


8.25 


5 


114 


686 





r 


n 


6/27/29 


19.9 


34.3 


8.15 


7 




688 


100 


r 


n 


6/27/29 


13.0 


34.5 


8.00 


91 




689 





r 


p 


6/27/29 


19.9 


34.3 


8.15 


7 


115 


692 





r 


n 


6/29/29 


20.6 


34.6 


8.19 


4 




693 


50 


r 


n 


6/29/29 


17.5 


34.6 


8.12 


17 




694 


100 


oc 


n 


6/29/29 


15.6 


34.6 


8.08 


27 


115a 


700 





c 


n 


6/30/29 


(18.0) 
(18.0) 


(34.3) 
(34.3) 


(8.18) 
(8.18) 


W* 




702 





oc 


n 


6/30/29 


(4)* 


116 


703 


50 


c 


n 


7/ 1/29 


10.6 


33.8 


8.11 


23 




706 


50 


oc 


p 


7/ 1/29 


10.6 


33.8 


8.11 


23 




704 


100 


oc 


n 


7/ 1/29 


6.7 


33.8 




. . 




707 


100 


oc 


P 


7/ 1/29 


6.7 


33.8 






117 


710 


100 


r 


n 


7/ 3/29 


8.8 


34.1 


7.98 


84 




713 


100 


r 


P 


7/ 3/29 


8.8 


34.1 


7.98 


84 


118 


714 





oc 


P 


7/ 5/29 


10.2 


33.6 


8.21 


90 




716 


100 


r 


n 


7/ 5/29 


6.1 


33.8 


7.94 


114 




718 


50 


r 


P 


7/ 5/29 


8.2 


33.7 


8.21 


92 


119 


720 





oc 


n 


7/ 7/29 


6.9 


33.0 


7.96 


142 




723 





oc 


p 


7/ 7/29 


6.9 


33.0 


7.96 


142 


121 


732 





oc 


n 


7/11/29 


7.5 


32.9 


7.98 


141 




735 





r 


p 


7/11/29 


7.5 


32.9 


7.98 


141 




734 


100 


r 


n 


7/11/29 


2.1 


33.2 


7.86 


184 


122 


738 





r 


n 


7/13/29 


8.2 


32.8 


7.98 


130 




741 





r 


P 


7/13/29 


8.2 


32.8 


7.98 


130 




739 


50 


r 


n 


7/13/29 


3.6 


33.1 


7.94 


142 




743 


100 


r 


P 


7/13/29 


2.4 


33.1 


7.90 


161 



a Surface values for station 6. 



to Surface values for station 11. 



62 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Table 4. Distributional and environmental records for Peridinium depressum var. parallelum Broch 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 
(°C) 


Salinity 
(o/oo) 


PH 


PO4 

mg/m3 










Atli 


intic 










6h 


55 





c 


n 


7/11/28 










8 


59 





oc 


n 


7/15/28 


10.32 


35.23 


7.93 


13 




60 


50 


oc 


n 


7/15/28 


9.08 


35.25 


7.95 


27 




61 


100 


c 


n 


7/15/28 


8.44 


35.25 


7.95 


54 


9 


64 





c 


n 


7/28/28 


11.12 


35.14 


8.08 


20 




65 


50 


oc 


n 


7/28/28 


8.06 


35.11 


7.96 


55 




66 


100 


oc 


n 


7/28/28 


7.62 


35.11 


7.98 


56 


11 


73 





oc 


n 


8/ 1/28 


10.67 


34.91 


8.06 


27 




74 


50 


c 


n 


8/ 1/28 


7.01 


34.97 


7.92 


63 




76 


50 


r 


P 


8/ 1/28 


7.01 


34.97 


7.92 


63 


12 


82 





oc 


P 


8/ 5/28 


8.44 


33.65 


8.10 


27 


13 


85 


50 


c 


n 


8/ 7/28 


-1.64 


33.40 


7.87 


59 




87 





r 


P 


8/ 7/28 


11.27 


32.68 


8.09 


19 


13a 


89 





oc 


n 


8/ 9/28 


(21.18) 


(35.23) 


(8.18) 


(H) a 


14 


94 


100 


oc 


n 


8/ 9/28 


14.02 


35.59 


8.06 


34 


15 


102 


100 


r 


n 


8/11/28 


18.45 


36.45 


8.19 


15 


16 


108 


100 


oc 


n 


8/13/28 


19.62 


36.48 


8.17 


13 


18 


118 


50 


r 


n 


8/17/28 


22.4 


36.8 


8.24 


5 


21 


134 


100 


r 


P 


8/24/28 


21.0 


36.8 


8.20 


7 




137 


100 


r 


n 


8/24/28 


21.0 


36.8 


8.20 


7 


23 


149 


50 


r 


n 


8/29/28 


20.9 


36.0 


8.14 


13 










Pacific 










128 


773 





oc 


n 


7/25/29 


16.4 


33.0 


8.12 


29 


130 


784 





r 


P 


9/ 4/29 


16.2 


33.4 


8.34 


36 




782 


50 


c 


n 


9/ 4/29 


11.7 


33.4 


8.26 


83 




785 


50 


c 


P 


9/ 4/29 


11.7 


33.4 


8.26 


83 




783 


100 


oc 


n 


9/ 4/29 


8.8 


33.7 


8.06 


176 



a Surface values for station 14. 






Table 5. Distributional and environmental records for Peridinium depressum var. convexius n.var. 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

rc) 


Salinity 
(0/00) 


PH 


mg/m 3 










Atlantic 










lb 


8 


100 


oc 


n 5/16/28 


(20.00) 


(36.50) 


(8.15) 


(30)* 


14 


92 


50 


r 


p 8/ 9/28 


14.95 


35.10 


8.18 


16 


16 


108 


100 


r 


n 8/13/28 
Pacific 


19.62 


36.48 


8.17 


13 


39 


226 


50 


r 


n 11/ 6/28 


16.3 


34.6 


7.92 


48 


69 


424 





oc 


n 1/12/29 


21.1 


35.2 


8.12 


62 




425 


50 


oc 


n 1/12/29 


17.4 


35.1 


7.99 


151 




426 


100 


oc 


n 1/12/29 


14.6 


34.8 


7.86 


198 




427 





oc 


p 1/12/29 


21.1 


35.2 


8.12 


62 




428 


50 


r 


p 1/12/29 


17.4 


35.1 


7.99 


151 




429 


100 


oc 


p 1/12/29 


14.6 


34.8 


7.86 


198 


70 


431 





oc 


n 1/13/29 


21.2 


35.1 


8.05 


103 




432 


50 


oc 


n 1/13/29 


15.4 


35.0 


7.88 


178 




433 


100 


oc 


n 1/13/29 


12.6 


34.8 


7.68 


233 




434 





c 


p 1/13/29 


21.2 


35.1 


8.05 


103 




435 


50 


r 


p 1/13/29 


15.4 


35.0 


7.88 


178 




436 


100 


r 


p 1/13/29 


17.6 


34.8 


7.68 


233 


109 


656 


100 


oc 


n 5/29/29 


27.4 


35.0 


8.23 


3 




659 


100 


r 


p 5/29/29 


27.4 


35.0 


8.23 


3 


110 


662 


50 


r 


n 5/31/29 


18.4 


34.8 


8.16 


7 




663 


100 


oc 


n 5/31/29 


17.9 


34.7 


8.14 


11 




665 


50 


oc 


p 5/31/29 


18.4 


34.8 


8.16 


7 


111 


668 





oc 


n 6/ 3/29 


20.1 


34.5 


8.18 


5 




669 


50 


oc 


n 6/ 3/29 


19.4 


34.6 


8.17 


5 




670 


100 


oc 


n 6/ 3/29 


18.2 


34.7 


8.13 


13 


112 


675 


50 


oc 


n 6/ 5/29 


21.7 


34.6 


8.23 


7 




676 


100 


oc 


n 6/ 5/29 


19.8 


34.7 


8.20 


8 




678 


50 


r 


p 6/ 5/29 


21.7 


34.6 


8.23 


7 


116 


704 


100 


r 


n 7/ 1/29 


6.7 


33.8 


. . . 





DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



63 



Table 6. Distributional and environmental records for Peridinium claudicanoides n.sp. 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 
(°C) 



Salinity 
(o/oo) 



PH 



PO4 
mg/m3 



1 


1 





oc 


la 


5 





r 


2 


14 





c 


3 


19 


100 


r 


32 


196 


1Q0 


r 


35 


204 


50 


r 


35a 


208 





r 


35b 


212 





r 


40 


229 





r 




230 


50 


r 




231 


100 


r 




232 





r 




233 


50 


r 



Atlantic 










5/12/28 
5/14/28 
5/18/28 


24.17 


36.23 


8.16 


34 


20.50 


36.40 


8.23 


58 


5/21/28 


13.79 


35.91 


8.10 


50 


10/ 5/28 


22.2 


36.4 


8.10 


30 


Pacific 










10/26/28 


16.8 


34.7 


7.92 


138 


10/26/28 


(27.0) 


(30.0) 


(8.25) 


(15 


10/28/28 


(27.0) 


(30.0) 


(8.25) 


(15 


11/ 8/28 


22.2 


33.7 


8.21 


24 


11/ 8/28 


15.3 


34.9 


7.87 


161 


11/ 8/28 


13.9 


35.0 


7.85 


159 


11/ 8/28 


22.2 


33.7 


8.21 


24 


11/ 8/28 


15.3 


34.9 


7.87 


161 



Table 7. Distributional and environmental records for Peridinium oceanicum 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

(°C) 


Salinity 
(0/00) 


PH 


mg/m 3 










Atli 


untie 










9 


64 





c 


n 


7/28/28 


11.12 


35.14 


8.08 


20 




65 


50 


a 


n 


7/28/28 


8.06 


35.11 


7.96 


55 




66 


100 


c 


n 


7/28/28 


7.62 


35.11 


7.98 


56 


10 


68 





oc 


n 


7/30/28 


10.94 


34.95 


8.08 


28 




69 


50 


c 


n 


7/30/28 


9.86 


34.94 


8.04 


34 




70 


100 


oc 


n 


7/30/28 


6.56 


35.02 


7.95 


52 


11 


73 





c 


n 


8/ 1/28 


10.67 


34.91 


8.06 


27 




74 


50 


c 


n 


8/ 1/28 


7.01 


34.97 


7.92 


63 




75 





oc 


P 


8/ 1/28 


10.67 


34.91 


8.06 


27 




76 


50 


r 


P 


8/ 1/28 


7.01 


34.96 


7.92 


63 




77 


100 


r 


P 


8/ 1/28 


6.26 


35.05 


7.90 


67 


11a 


78 





r 


n 


8/ 2/28 


(10.67) 


(34.91) 


(8.06) 


(27) a 


12 


80 


50 


oc 


n 


8/ 5/28 


3.95 


34.74 


7.96 


78 


15 


102 


100 


oc 


n 


8/11/28 


18.50 


36.45 


8.19 


15 


16 


108 


100 


r 


n 


8/13/28 


19.62 


36.48 


8.17 


13 u 


20a 


131 





r 


n 


8/23/28 


(26.57) 


(36.28) 


(8.32) 


(4) b 


21 


137 


100 


r 


n 


8/24/28 


21.00 


36.75 


8.20 


7 



a Surface values for station 11. 



Surface values for station 21. 



Table 8. Distributional and environmental records for Peridinium oceanicum var. tenellum 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 
(°C) 



Salinity 
(0/00) 



pH 



PO /4 3 

mg/m° 



la 


4 





r 




5 





oc 


lb 


6 





oc 




7 


50 


oc 




8 


100 


r 


2 


14 





oc 


3 


20 





oc 




18 


50 


oc 




19 


100 


r 


6 


36 


50 


oc 


6a 


46 





oc 


6b 


44 





oc 




45 





c 


6c 


49 





r 


8 


60 


50 


a 




61 


100 


oc 


13a 


89 





r 


14 


91 


100 


r 




92 


50 


r 




94 


100 


r 




95 


50 


c 


15 


99 


100 


r 


16 


107 


50 


oc 




108 


100 


r 


31 


193 


100 


oc 



Atlantic 
5/14/28 
5/14/28 
5/16/28 
5/16/28 
5/16/28 
5/18/28 
5/21/28 
5/21/28 
5/21/28 
5/31/28 
5/31/28 
6/ 2/28 
6/ 2/28 
6/ 4/28 
7/15/28 
7/15/23 
8/ 8/28 
8/ 9/28 
8/ 9/28 
8/ 9/28 
8/ 9/28 
8/11/28 
8/13/28 
8/13/28 
10/ 3/28 



20.50 

15.50 

14.66 

13.65 

11.62 

(12.44) 

(12.44) 

(12.44) 

(12.44) 

9.08 

8.44 

(21.18) 

14.02 

14.95 

14.02 

14.95 

18.45 

23.64 

19.62 

22.56 



36.40 
36.06 
35.96 
35.89 
35.51 
(35.55) 
(35.55) 
(35.55) 
(35.55) 
35.25 
35.25 
(35.23) 
35.59 
35.10 
35.59 
35.10 
36.45 
36.41 
36.48 
35.51 



8.23 
8.15 
8.19 
8.10 
8.12 

(8.15) 
8.15) 

(8.15) 

(8.15) 
7.95 
7.95 

(8.18) 
8.06 
8.18 
8.06 
8.18 
8.19 
8.23 
8.17 
8.19 



58 
99 
30 
48 
32 
21V 
21) 
21 
(21) : 
27 

54 1 
(ll) 1 

34 

16 

34 

16 

15 

8 

13 

28 



64 STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 

Table 8. Distributional and environmental records for 
Peridinium oceanicum var. tenellum- -Continued 



Station 


Sample 


Depth 

(m) 


Relative 
abundance 


Apparatus Date 


Temperature 

(°C) 


Salinity 
(o/oo) 


PH 


p °4, 
mg/m 3 










Atlant 


ic --Concluded 








32 


195 


50 


r 


n 
P 


10/ 5/28 
acif ic 


27.2 


36.0 


8.24 


2 


40 


230 


50 


r 


n 


11/ 8/28 


15.3 


34.9 


7.87 


161 




231 


100 


r 


n 


11/ 8/28 


13.9 


35.0 


7.85 


159 




232 





oc 


P 


11/ 8/28 


22.2 


33.7 


8.21 


24 




235 





r 


n 


11/ 8/28 


22.2 


33.7 


8.21 


24 


41 


236 


50 


r 


n 


11/10/28 


14.6 


35.0 


7.94 


58 




238 





r 


p 


11/10/28 


20.4 


34.2 


8.11 


32 




239 


100 


r 


p 


11/10/28 


14.5 


35.0 


7.91 


152 


41a 


240 





oc 


n 


11/12/28 


(18.7) 
(18.7) 


(34.7) 
(34.7) 


(8.06) 
(8.06) 


(45) c 
(45) 


42 


241 





r 


n 


11/13/28 




242 


50 


r 


n 


11/13/28 


17.2 


34.9 


7.99 


68 




243 


100 


r 


n 


11/13/28 


13.8 


35.0 


7.91 


150 


43 


246 


100 


r 


n 


11/15/28 


13.6 


35.0 


7.90 


92 




247 





r 


P 


11/15/28 


19.6 


34.8 


8.09 


52 


44 


253 





r 


P 


11/17/28 


20.7 


34.9 


8.03 


38 


45 


256 





r 


n 


11/19/28 


22.4 


35.3 


8.12 


38 




257 


50 


r 


n 


11/19/28 


22.4 


35.2 


8.13 


46 




258 


100 


r 


n 


11/19/28 


18.6 


35.1 


8.00 


50 




259 





oc 


p 


11/19/28 


22.4 


35.3 


8.12 


38 




260 


50 


r 


P 


11/19/28 


22.4 


35.2 


8.13 


46 


46 


261 





oc 


n 


11/21/28 


23.3 


35.3 


8.16 


36 




262 


50 


r 


n 


11/21/28 


23.2 


35.3 


8.16 


40 




263 


100 


r 


n 


11/21/28 


22.5 


35.4 


8.17 


40 




264 





r 


P 


11/21/28 


23.3 


35.3 


8.16 


36 




265 


50 


r 


p 


11/21/28 


23.2 


35.3 


8.16 


40 


47 


266 





r 


n 


11/23/28 


23.9 


36.0 


8.23 


17 




267 


50 


oc 


n 


11/23/28 


23.8 


36.0 


8.23 


20 




268 


100 


oc 


n 


11/23/28 


22.7 


36.2 


8.23 


20 




269 





oc 


P 


11/23/28 


23.9 


36.0 


8.23 


17 


48 


273 


100 


oc 


n 


11/25/28 


22.7 


36.2 


8.23 


20 


53a 


310 





r 


n 


12/10/28 










58 


346 


100 


r 


p 


12/20/28 


14.3 


34.4 


8.*10 


40 


61 


364 


50 


oc 


n 


12/28/28 


14.0 


34.0 


8.05 


60 




365 


100 


r 


n 


12/28/28 


10.8 


34.0 


8.03 


80 


62 


372 


50 


r 


n 


12/30/28 


16.2 


34.3 


8.10 


28 


71 


438 





oc 


n 


2/ 6/29 


23.5 


35.2 


8.13 


58 




439 


50 


oc 


n 


2/ 6/29 


16.7 


35.1 


7.90 


150 




440 


100 


r 


n 


2/ 6/29 


13.9 


35.0 


7.71 


220 




441 





oc 


P 


2/ 6/29 


23.5 


35.2 


8.13 


58 


72 


445 


100 


r 


n 


2/ 6/29 


13.9 


35.0 


7.71 


220 


73 


450 





oc 


n 


2/10/29 


25.3 


35.4 


8.21 


44 




451 


50 


r 


n 


2/10/29 


18.7 


35.4 


8.05 


122 




453 


100 


r 


n 


2/10/29 


14.7 


35.0 


7.80 


178 


74 


458 


100 


r 


n 


2/12/29 


15.4 


35.1 


7.80 


175 


75 


462 





r 


n 


2/14/29 


22.8 


35.8 


8.18 


44 


76 


467 





r 


n 


2/16/29 


23.4 


35.9 


8.15 


50 




471 


50 


r 


p 


2/16/29 


22.1 


35.9 


8.14 


42 


77 


472 





oc 


n 


2/18/29 


23.7 


36.0 


8.19 


16 




473 





oc 


p 


2/18/29 


23.7 


36.0 


8.19 


16 




474 


50 


oc 


p 


2/18/29 


23.5 


36.0 


8.19 


16 


78 


475 





oc 


n 


2/20/29 


24.6 


36.0 


8.17 


32 




476 


50 


r 


n 


2/20/29 


23.8 


36.1 


8.14 


32 




477 


100 


oc 


n 


2/20/29 


21.9 


36.2 


8.14 


34 




478 





r 


p 


2/20/29 
2722/29 


24.6 


36.0 


8.17 


32 


79 


481 





oc 


n 


25.2 


36.0 


8.17 


34 




482 





oc 


n 


2/22/29 


25.2 


36.0 


8.17 


34 




483 


100 


oc 


n 


2/22/29 


21.8 


36.2 


8.13 


45 




484 





r 


P 


2/22/29 


25.2 


36.0 


8.17 


34 




485 


50 


r 


P 


2/22/29 


24.5 


36.1 


8.17 


34 


80 


486 





oc 


n 


2/24/29 


26.0 


35.9 


8.20 


36 




488 





oc 


P 


2/24/29 


26.0 


35.9 


8.20 


36 


81 


491 





oc 


n 


2/26/29 


26.5 


35.8 


8.19 


38 




492 


50 


r 


n 


2/26/29 


26.4 


35.9 


8.19 


38 




493 





r 


p 


2/26/29 


26.5 


35.8 


8.19 


38 




494 


50 


r 


P 


2/28/29 


26.4 


35.9 


8.19 


38 




495 


100 


r 


p 


2/26/29 


23.6 


36.2 


8.18 


36 


82 


497 


50 


oc 


n 


2/28/29 


27.2 


36.3 


8.21 


34 


97 


574 





oc 


n 


4/28/29 


28.3 


35.2 


8.16 


24 




575 


50 


r 


n 


4/28/29 


28.0 


35.4 


8.16 


21 




576 


100 


r 


n 


4/28/29 


27.6 


35.6 


8.15 


25 


98 


581 





r 


n 


4/30/29 


27.0 


35.3 


8.16 


24 




583 


100 


r 


n 


4/30/29 


26.7 


35.4 


8.14 


32 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



65 



Table 8. Distributional and environmental records for 
Peridinium oceanicum var. tenellum- -Concluded 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 
(°C) 


Salinity 
(o/oo) 


PH 


po 4 

mg/m 3 










Pacific 


--Concluded 








98 


584 





r 


P 


4/30/29 


27.0 


35.3 


8.16 


24 




588 


100 


r 


P 


4/30/29 


26.7 


35.4 


8.14 


32 


99 


589 





r 


n 


5/ 2/29 


27.9 


34.9 


8.21 


12 




590 


50 


r 


n 


5/ 2/29 


27.8 


34.9 


8.22 


12 




592 





r 


P 


5/ 2/29 


27.9 


34.9 


8.21 


12 




594 


100 


r 


P 


5/ 2/29 


27.8 


35.0 


8.22 


17 




595 





r 


n 


5/ 2/29 


27.9 


34.9 


8.21 


12 


100 


596 


50 


c 


n 


5/ 4/29 


27.6 


34.7 


8.21 


10 




597 


100 


oc 


n 


5/ 4/29 


27.6 


34.7 


8.22 


12 


115 


693 


50 


oc 


n 


6/29/29 


17.5 


34.6 


8.12 


17 




697 


50 


r 


p 


6/29/29 


17.5 


34.6 


8.12 


17 


115a 


700 





r 


n 


6/30/29 


(18.0) 


(34.3) 


(8.18) 


(4)* 


116 


704 


100 


oc 


n 


7/ 1/29 


6.7 


33.8 






117 


709 


50 


oc 


n 


7/ 3/29 


12.5 


34.2 


8.06 


51 




712 


50 


oc 


P 


7/ 3/29 


12.5 


34.2 


8.06 


51 


127 


767 





oc 


n 


7/23/29 


13.4 


32.7 


8.12 


43 




768 


50 


r 


n 


7/23/29 


10.5 


32.8 


8.09 


56 




771 


50 


r 


P 


7/23/29 


10.5 


32.8 


8.09 


56 




769 


100 


r 


n 


7/23/29 


8.2 


32.8 


8.00 


72 


128 


773 





oc 


n 


7/25/29 


16.4 


33.0 


8.12 


29 




776 





oc 


P 


7/25/29 


16.4 


33.0 


8.12 


29 




775 


100 


oc 


n 


7/25/29 


10.2 


33.2 


8.06 


46 


130 


783 


100 


r 


n 


9/ 4/29 


8.8 


33.7 


8.06 


176 




792 





r 


P 


9/ 4/29 


16.2 


33.4 


8.34 


36 


131 


788 





r 


n 


9/ 6/29 


19.3 


33.4 


8.34 






793 





r 


P 


9/ 6/29 


19.3 


33.4 


8.34 




151 


938 


50 


r 


n 


9/ 6/29 


18.3 


34.4 






152 


945 


50 


r 


n 


10/27/29 


14.2 


34.5 


7.87 


53 




946 


100 


r 


n 


10/27/29 


11.4 


34.7 


7.76 


75 


155 


973 


50 


r 


p 


11/ 2/29 


27.7 


34.9 


8.30 


30 


156 


974 


100 


r 


n 


11/ 4/29 


26.4 


35.1 


8.30 


48 


157 


978 





oc 


n 


11/ 6/29 


27.1 


35.3 


8.27 


47 




979 


50 


r 


n 


11/ 6/29 


27.1 


35.2 


8.32 


60 




980 


100 


r 


n 


11/ 6/29 


26.8 


35.5 


8.30 


64 


158 


983 





r 


n 


11/ 8/29 


28.2 


35.6 


8.34 


36 




984 


50 


r 


n 


11/ 8/29 


28.2 


35.6 


8.39 


50 




985 


100 


r 


n 


11/ 8/29 


27.6 


35.9 


8.39 


48 


159 


990 





r 


n 


11/11/29 


28.6 


35.7 


8.37 


15 




991 


50 


r 


n 


11/11/29 


28.5 


35.7 


8.39 


35 




992 


100 


r 


n 


11/11/29 


28.0 


35.7 


8.37 


23 



a Surface values for station 6. " Surface values for station 14. c Values of station 42. 



Table 9. Distributional and environmental records for Peridinium crassipes Kofoid 



Station 


Sample 


Depth 


Relative 
abundance 


Apparatus 


Date 


Temperature 

(°C) 


Salinity 
(o/oo) 


PH 


po 4 

mg/m 3 










Pa 


cif ic 










35 


204 


50 


r 


n 


10/26/28 


16.8 


34.7 


7.92 


138 


36 


213 





r 


n 


10/30/28 


26.5 


31.6 


8.23 


16 


37 


218 


50 


r 


n 


11/ 1/28 


18.8 


34.5 


8.00 


121 




221 


50 


r 


p 


11/ 1/28 


18.8 


34.5 


8.00 


121 


40 


234 


100 


r 


p 


11/ 8/28 


13.9 


35.0 


7.85 


159 


41 


237 


100 


oc 


n 


11/10/28 


14.5 


35.0 


7.91 


152 


44 


254 


50 


r 


p 


11/17/28 


20.4 


34.9 


8.04 


34 


45 


256 





r 


n 


11/19/28 


22.4 


35.3 


8.12 


38 




257 


50 


r 


n 


11/19/28 


22.4 


35.2 


8.13 


46 




258 


100 


r 


n 


11/19/28 


18.6 


35.1 


8.00 


50 


48 


271 





oc 


n 


11/25/28 


23.6 


36.4 


8.23 


13 




272 


50 


r 


n 


11/25/28 


23.6 


36.4 


8.24 


16 




273 


100 


r 


n 


11/25/28 


22.7 


36.3 


8.26 


16 


49 


277 





r 


n 


11/27/28 


23.4 


36.2 


8.27 


13 


49a 


283 





r 


n 


11/28/28 


(23.2) 


(36.0) 


(8.23) 


(13)* 


58 


346 


100 


r 


p 


12/22/28 


12.3 


34.1 


8.05 


40 


60 


359 


• ••• 


r 


p 


12/22/28 


12.3 


34.1 


8.05 


40 


61 


364 


50 


r 


n 


12/28/28 


14.0 


34.0 


8.05 


60 




365 


100 


r 


n 


12/28/28 


10.8 


34.0 


8.03 


80 


62 


372 


50 


r 


n 


12/30/28 


16.2 


34.3 


8.10 


28 




373 


100 


r 


n 


12/30/28 


13.1 


34.2 


8.06 


48 


69 


424 





r 


n 


1/12/29 


21.1 


35.2 


8.12 


62 




425 


50 


oc 


n 


1/12/29 


17.4 


35.1 


7.99 


151 




426 


100 


oc 


n 


1/12/29 


14.6 


34.8 


7.86 


198 



66 STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Table 9. Distributional and environmental records for Peridinium crassipes Kofoid- -Continued 


Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 
(°C) 


Salinity 
(o/oo) 


PH 


mg/m^ 










Pacific 


--Continued 








77 


472 





oc 


n 


2/18/29 


23.7 


36.0 


8.19 


16 


78 


477 


100 


r 


n 


2/20/29 


21.9 


36.2 


8.14 


34 


84 


506 


50 


r 


n 


3/ 4/29 


27.5 


36.4 


8.21 


24 


86 


517 


50 


r 


n 


3/ 9/29 


27.4 


36.2 


8.29 


17 


97 


574 





oc 


n 


4/28/29 


28.3 


35.2 


8.16 


24 




575 


50 


oc 


n 


4/28/29 


28.0 


35.4 


8.16 


21 




576 


100 


oc 


n 


4/28/29 


27.6 


35.6 


8.15 


25 




578 


50 


r 


P 


4/28/29 


28.0 


35.4 


8.16 


21 




579 


100 


r 


P 


4/28/29 


27.6 


35.6 


8.15 


25 


98 


583 


100 


oc 


n 


4/30/29 


26.7 


35.4 


8.14 


32 




584 





oc 


P 


4/30/29 


27.0 


35.3 


8.16 


24 


99 


589 





r 


n 


5/ 2/29 


27.9 


34.9 


8.21 


12 




590 


50 


oc 


n 


5/ 2/29 


27.8 


34.9 


8.22 


12 




591 


100 


oc 


n 


5/ 2/29 


27.8 


35.0 


8.22 


17 




595 





oc 


n 


5/ 2/29 


27.9 


34.9 


8.21 


12 


100 


596 


50 


oc 


n 


5/ 4/29 


27.6 


34.7 


8.21 


10 




597 


100 


oc 


n 


5/ 4/29 


27.6 


34.7 


8.22 


12 




602 


100 


r 


P 


5/ 4/29 


27.6 


34.7 


8.22 


12 


101 


603 





oc 


n 


5/ 7/29 


26.3 


34.7 


8.24 


8 




604 


50 


oc 


n 


5/ 7/29 


26.2 


34.7 


8.24 


8 




605 


100 


oc 


n 


5/ 7/29 


25.2 


35.1 


8.25 


8 


102 


609 





oc 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




610 


50 


oc 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 


103 


615 





oc 


n 


5/11/29 


26.0 


35.0 


8.25 


5 




616 


50 


oc 


n 


5/11/29 


25.8 


35.2 


8.25 


5 




617 


100 


r 


n 


5/11/29 


24.8 


35.2 


8.25 


5 




620 


100 


r 


P 


5/11/29 


24.8 


35.2 


8.25 


5 


104 


621 





oc 


n 


5/13/29 


26.1 


35.2 


8.24 


7 




623 


100 


oc 


n 


5/13/29 


25.3 


35.3 


8.21 


7 


105 


627 


50 


oc 


n 


5/15/29 


26.9 


34.9 


8.23 


5 




628 


50 


r 


n 


5/15/29 


26.9 


34.9 


8.23 


5 




629 


100 


oc 


n 


5/15/29 


25.2 


35.1 


8.23 


5 


106 


633 





r 


n 


5/17/29 


27.2 


35.0 


8.23 


5 




634 


50 


oc 


n 


5/17/29 


27.0 


35.0 


8.23 


5 




635 


100 


oc 


n 


5/17/29 


25.6 


35.1 


8.23 


5 


107 


639 





oc 


n 


5/19/29 


28.0 


34.4 


8.23 


5 




640 





oc 


n 


5/19/29 


28.0 


34.4 


8.23 


5 




641 





r 


n 


5/19/29 


28.0 


34.4 


8.23 


5 


132 


789 


50 


oc 


n 


9/ 8/29 


17.6 


33.9 


8.33 


19 




799 


100 


oc 


n 


9/ 8/29 


14.3 


33.4 


8.30 


16 


133 


805 


50 


r 


n 


9/10/29 


20.8 


34.7 


8.37 


7 


134 


809 


50 


r 


n 


9/12/29 


19.8 


34.6 


8.34 


6 




810 


100 


r 


n 


9/12/29 


18.1 


34.6 


8.34 


6 




817 


100 


r 


P 


9/12/29 


18.1 


34.6 


8.34 


6 


135 


821 


50 


r 


n 


9/14/29 


21.5 


35.0 


8.37 


5 




822 


100 


r 


n 


9/14/29 


18.7 


34.8 


8.34 


5 


136 


827 





r 


n 


9/16/29 


24.6 


35.4 


8.37 


3 




828 


50 


oc 


n 


9/16/29 


21.4 


35.1 


8.39 


3 




829 


100 


oc 


n 


9/16/29 


18.6 


35.0 


8.39 


3 


139 


850 


50 


oc 


n 


9/22/29 


25.8 


34.9 


8.31 


6 


140 


857 


50 


r 


n 


10/ 3/29 


26.9 


35.0 


8.39 


7 




862 


100 


r 


P 


10/ 3/29 


25.5 


35.0 


8.34 


7 


141 


864 





r 


n 


10/ 5/29 


25.9 


35.2 


8.34 


5 




865 


50 


r 


n 


10/ 5/29 


24.8 


35.3 


8.34 


5 


142 


874 


100 


oc 


n 


10/ 7/29 


16.6 


34.4 


8.27 


7 


149 


921 


50 


r 


n 


10/21/29 


23.3 


35.0 


8.37 


6 


150 


929 





oc 


n 


10/25/29 


25.6 


34.7 


8.39 


7 




930 


50 


r 


n 


10/25/29 


22.8 


34.8 


8.35 


10 




931 


100 


r 


n 


10/25/29 


19.6 


34.6 


8.32 


11 


151 


937 





r 


n 


10/26/29 


26.0 


34.0 








938 


50 


r 


n 


10/26/29 


18.3 


34.4 








939 


100 


r 


n 


10/26/29 


12.5 


34.6 








942 


50 


r 


P 


10/26/29 


18.3 


34.4 








944 





r 


n 


10/27/29 


27.4 


33.7 


8.35 


20 


152 


946 


100 


r 


n 


10/27/29 


11.4 


34.7 


7.76 


75 


153 


951 





r 


n 


10/29/29 


28.1 


34.2 


8.47 


7 




955 





r 


p 


10/29/29 


28.1 


34.2 


8.47 


7 




952 


50 


r 


n 


10/29/29 


28.2 


34.2 


8.40 


7 




953 


100 


r 


n 


10/29/29 


25.3 


34.8 


7.93 


21 


154 


959 


50 


r 


n 


10/31/29 


28.2 


34.2 


8.40 


7 




960 


100 


r 


n 


10/31/29 


25.3 


34.8 


7.93 


21 


155 


965 





oc 


n 


11/ 2/29 


27.8 


34.9 


8.29 


29 




966 


50 


oc 


n 


11/ 2/29 


27.7 


34.9 


8.30 


30 




967 


100 


r 


n 


11/ 2/29 


27.2 


35.0 


8.30 


35 


156 


973 


50 


oc 


n 


11/ 4/29 


27.0 


35.1 


8.37 


46 




974 


100 


r 


n 


11/ 4/29 


26.4 


35.1 


8.30 


48 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



67 



Table 9. Distributional and environmental records for Peridinium crassipes Kofoid- -Concluded 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 
(°C) 











Pacil 


ic --Concluded 
11/ 6/29 




157 


978 





oc 


n 


27.1 




979 


50 


oc 


n 


11/ 6/29 


27.1 




980 


100 


oc 


n 


11/ 6/29 


26.8 


158 


983 





r 


n 


11/ 8/29 


28.2 




985 


100 


oc 


n 


11/ 8/29 


27.6 


160 


1002 


50 


r 


n 


11/13/29 


28.6 



Salinity 
(o/oo) 



35.3 
35.2 
35.5 
35.6 
35.9 
35.6 



PH 



8.27 
8.32 
8.30 
8.34 
8.39 
8.39 



P °/ 4 3 
mg/m 



47 
60 
64 
36 
48 
15 



Table 10. Distributional and environmental records for Peridinium truncatum n.sp. 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 

(°C) 



Salinity 
(o/oo) 



PH 



p 04 

mg/m^ 



35 


203 





oc 




204 


50 


r 




205 


100 


r 




206 





oc 


35a 


208 





oc 




211 





c 




212 





oc 


36 


213 





oc 




214 


50 


r 




215 


100 


r 


37 


217 





oc 




218 


50 


r 




219 


100 


r 


42 


241 





r 


80 


486 





r 


91 


541 


50 


r 


92 


546 


50 


oc 


95 


564 


100 


r 


96 


569 


50 


r 


97 


575 


50 


oc 




578 


50 


r 


99 


589 





r 




590 


50 


r 




592 





r 




593 


50 


r 




595 





oc 


100 


596 


50 


oc 


104 


623 


100 


r 


105 


629 


100 


r 


112 


675 


50 


r 


137 


837 


50 


r 


141 


865 


50 


oc 


151 


942 


50 


r 


155 


965 





oc 




966 


50 


oc 




967 


100 


oc 


156 


972 





oc 




973 


50 


oc 


157 


978 





c 




979 


50 


c 




980 


100 


r 


158 


984 


50 


r 




985 


100 


r 


159 


990 





r 




991 


50 


r 




992 


100 


r 



Pacific 

10/26/28 

10/26/28 

10/26/28 

10/26/28 

10/26/28 

10/26/28 

10/26/28 

10/30/28 

10/30/28 

10/30/28 

11/ 1/28 

11/ 1/28 

11/ 1/28 

11/13/28 

2/24/29 

3/27/29 

3/29/29 

4/24/29 

4/26/29 

4/28/29 

4/28/29 

5/ 2/29 

5/ 2/29 

5/ 2/29 

5/ 2/29 

5/ 2/29 

5/ 4/29 

5/13/29 

5/15/29 

6/ 5/29 

9/18/29 

10/ 5/29 

10/26/29 

11/ 2/29 

11/ 2/29 

11/ 2/29 

11/ 4/29 

11/ 4/29 

11/ 6/29 

11/ 6/29 

11/ 6/29 

11/ 8/29 

11/ 8/29 

11/11/29 

11/11/29 

11/11/29 



27.4 
16.8 
14.4 
27.4 
27.0 
27.0 
27.0 
26.5 
18.5 
14.4 
27.1 
18.8 
15.1 
18.7 
26.0 
28.4 
28.4 
28.5 
29.2 
28.0 
28.0 
27.9 
27.8 
27.9 
27.8 
27.9 
27.6 
25.3 
25.2 
21.7 
24.4 
24.8 
18.3 
27.8 
27.7 
27.2 
27.6 
27.0 
27.1 
27.1 
26.8 
28.2 
27.6 
28.6 
28.5 
28.0 



29.7 


8.31 


15 


34.7 


7.92 


138 


34.9 


7.88 


189 


29.7 


8.31 


15 


(30.0) 


(8.26) 
(8.26) 


(15)* 


30.0) 


15* 


(30.0) 


(8.26) 


(15)* 


31.6 


8.23 


16 


34.5 


8.03 


122 


34.9 


7.85 


149 


31.7 


8.28 


15 


34.5 


8.00 


121 


34.9 


7.82 


153 


34.7 


8.06 


45 


35.9 


8.20 


36 


35.4 


8.29 


28 


35.4 


8.29 


28 


35.4 


8.22 


21 


35.3 


8.23 


12 


35.4 


8.16 


21 


35.4 


8.16 


21 


34.9 


8.21 


12 


34.9 


8.22 


12 


34.9 


8.21 


12 


34.9 


8.22 


12 


34.9 


8.21 


12 


34.7 


8.21 


10 


35.3 


8,21 


7 


35.1 


8.23 


5 


34.6 


8.23 


7 


35.1 


8.34 


4 


35.3 


8.34 


5 


34.4 






34.9 


8.29 


29 


34.9 


8.30 


30 


35.0 


8.30 


35 


35.0 


8.34 


28 


35.1 


8.37 


46 


35.3 


8.27 


47 


35.2 


8.32 


60 


35.5 


8.30 


64 


35.6 


8.39 


50 


35.9 


8.39 


48 


35.7 


8.37 


15 


35.7 


8.39 


15 


35.7 


8.37 


23 



Table 11. Distributional and environmental records for Peridinium pallidum Ostenfeld 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 

(°C) 



Salinity 
(o/oo) 



P H 



mg/m J 











Atlantic 










3 


18 


50 


r 


n 5/21/28 


15.0 


36.1 


8.15 


99 




20 





oc 


n 5/21/28 


15.5 


36.1 


8.15 


99 


6b 


45 





r 


n 6/ 2/28 


10.2 


35.4 


8.11 


28 




46 





r 


n 6/ 2/28 


10.2 


35.4 


8.11 


28 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Table 11. Distributional and environmental records for Peridinium pallidum Ostenf eld- -Concluded 



Station 



Sample 



Depth 
(m) 



Relative 
abundance A PP ara ^ 



Date 



Temperature 

(°C) 



Salinity 
(o/oo) 



PH 



PO4 

mg/m3 











Atlantic 


--Concluded 










6e 


52 





r 


n 


7/ 8/28 


10.2 


35.4 


8.11 


28 


6g 


54 





r 


n 


7/10/28 


10.2 


35.4 


8.11 


28 


6h 


55 





oc 


n 


7/11/28 


10.2 


35.4 


8.11 


28 


7 


56 





oc 


n 


7/13/28 


8.9 


35.2 


8.08 


34 




57 


50 


oc 


n 


7/13/28 


8.2 


35.2 


8.03 


47 




58 


100 


c 


n 


7/13/28 


8.1 


35.2 


8.04 


57 


8 


60 


50 


oc 


n 


7/15/28 


9.1 


35.2 


7.95 


27 




61 


100 


r 


n 


7/15/28 


8.4 


35.3 


7.95 


54 


9 


64 





oc 


n 


7/28/28 


11.2 


35.1 


8.08 


20 




65 


50 


oc 


n 


7/28/28 


8.4 


35.1 


7.96 


55 




66 


100 


oc 


n 


7/28/28 


7.6 


35.1 


7.98 


56 


10 


68 





r 


n 


7/30/28 


10.9 


34.9 


8.08 


28 




69 


50 


r 


n 


7/30/28 


10.0 


34.9 


8.04 


39 


11a 


78 





oc 


n 


8/ 2/28 


9.1 


34.2 


8.08 


27 


12 


79 





r 


n 


8/ 5/28 


8.4 


33.6 


8.10 


27 




80 


50 


oc 


n 


8/ 5/28 


3.9 


34.7 


7.91 


95 




81 


100 


oc 


n 


8/ 5/28 


3.4 


34.9 


7.89 


82 




82 





oc 


P 


8/ 5/28 


8.4 


33.6 


8.10 


27 


13 


85 


50 


c 


n 


8/ 7/28 


-1.6 


33.4 


7.87 


59 




86 


100 


oc 


n 


8/ 7/28 


-1.2 


33.6 


7.87 


60 


14 


95 


50 


r 


n 


8/ 9/28 


15.0 


35.1 


8.18 


16 


16 


103 





r 


p 


8/13/28 


25.9 


36.2 


8.24 


8 




104 


50 


r 


p 


8/13/28 


24.4 


36.4 


8.25 


8 


17 


111 





r 


n 


8/15/28 


26.2 


36.6 


8.29 


9 










Pacific 










97 


575 


50 


oc 


n 


4/28/29 


28.0 


35.4 


8.16 


21 




576 


100 


r 


n 


4/28/29 


27.6 


35.6 


8.15 


25 




577 





oc 


P 


4/28/29 


28.3 


35.2 


8.16 


24 


98 


583 


100 


r 


n 


4/30/29 


26.7 


35.4 


8.14 


32 




584 





oc 


P 


4/30/29 


27.0 


35.3 


8.16 


24 


101 


604 


50 


oc 


n 


5/ 7/29 


26.2 


34.7 


8.24 


8 




605 


100 


oc 


n 


5/ 7/29 


25.2 


35.1 


8.23 


8 


102 


609 





oc 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




610 


50 


r 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




611 


100 


oc 


n 


5/ 9/29 


25.6 


35.0 


8.23 


8 




612 





r 


p 


5/ 9/29 


25.6 


35.0 


8.23 


8 


113 


682 


100 


oc 


n 


6/25/29 


21.5 


34.7 


8.23 


8 


114 


686 





r 


n 


6/27/29 


19.9 


34.3 


8.15 


7 




688 


100 


r 


p 


6/27/29 


13.0 


34.5 


8.00 


91 


116 


703 


50 


oc 


n 


7/ 1/29 


10.6 


33.8 


8.11 


23 




706 


50 


r 


P 


7/ 1/29 


10.6 


33.8 


8.11 


23 


117 


711 





r 


p 


7/ 3/29 


15.9 


34.3 


8.17 


3 




709 


50 


oc 


n 


7/ 3/29 


12.5 


34.2 


8.06 


51 




712 


50 


oc 


p 


7/ 3/29 


12.5 


34.2 


8.06 


51 




710 


100 


oc 


n 


7/ 3/29 


8.8 


34.1 


7.98 


84 


133 


806 


100 


r 


n 


9/10/29 


18.4 


34.8 


8.31 


7 




813 


50 


r 


p 


9/10/29 


20.8 


34.7 


8.37 


7 




808 





r 


n 


9/10/29 


22.7 


34.7 


8.47 


7 


134 


810 


100 


r 


n 


9/12/29 


18.1 


34.6 


8.34 


6 


135 


821 


50 


oc 


n 


9/14/29 


21.5 


35.0 


8.37 


5 


136 


828 


50 


r 


n 


9/16/29 


21.4 


35.1 


8.39 


3 




833 


50 


r 


p 


9/16/29 


21.4 


35.1 


8.39 


3 




834 


100 


oc 


p 


9/16/29 


18.6 


35.0 


8.39 


3 


137 


836 





oc 


n 


9/16/29 


25.5 


35.0 


8.39 


4 



Table 12. Distributional and environmental records for Ceratocorys horrida Stein 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 

(°C) 



Salinity 
(0/00) 



PH 



P ? 4 3 
mg/m° 











Atlantic 










1 


1 





oc 


n 


5/12/28 


24.0 


36.2 


8.16 


34 




2 


70 


r 


n 


5/12/28 


22.1 


36.5 


8.17 


39 


la 


4 





r 


4"n 


5/14/28 


(22.0) 


(36.3) 


(8.20) 


(45)* 


lb 


7 


50 


c 


n 


5/16/28 


(22.0) 


(36.3 


(8.20) 


(45)* 




8 


100 


oc 


n 


5/16/28 


(22.0) 


(36.3) 


(8.20) 


(45)* 


2 


13 


100 


r 


n 


5/18/28 


19.8 


36.4 


8.21 


33 




14 





oc 


n 


5/18/28 


20.5 


36.4 


8.23 


58 


15 


102 


100 


oc 


n 


8/11/28 


18.4 


36.4 


8.20 


19 


16 


103 





r 


p 


8/13/28 


25.9 


36.2 


8.24 


8 




104 


50 


r 


p 


8/13/28 


24.4 


36.4 


8.23 


8 




106 





oc 


n 


8/13/28 


25.9 


36.2 


8.24 


8 




107 


50 


oc 


n 


8/13/28 


24.4 


36.4 


8.23 


8 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



69 



Table 12. Distributional and environmental records for Ceratocorys horrida Stein- -Continued 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

(°C) 


Salinity 
(o/oo) 


pH 


P< ?4, 
mg/nv* 










Atlantic 


--Concluded 










108 


100 


r 


n 


8/13/28 


19.9 


36.5 


8.17 


13 


17 


109 





r 


P 


8/15/28 


26.2 


36.6 


8.29 


9 




110 


50 


r 


P 


8/15/28 


21.9 


36.6 


8.28 


12 




112 


50 


oc 


n 


8/15/28 


21.9 


36.6 


8.28 


12 




113 


100 


oc 


n 


8/15/28 


19.3 


36.5 


8.23 


9 


19 


122 





r 


n 


8/20/28 


26.6 


37.0 


8.34 


5 


20 


128 





oc 


n 


8/22/28 


26.1 


36.6 


8.37 


5 




129 


50 


r 


n 


8/22/28 


25.8 


36.6 


8.26 


3 




130 


100 


oc 


n 


8/22/28 


22.6 


36.7 


8.19 


5 


21 


132 





r 


p 


8/25/28 


26.6 


36.3 


8.32 


4 




134 


100 


r 


P 


8/25/28 


21.0 


36.8 


8.25 


4 




135 





oc 


n 


8/25/28 


26.6 


36.3 


8.32 


4 




137 


100 


r 


n 


8/25/28 


21.0 


36.8 


8.25 


4 


22 


139 





r 


P 


8/27/28 


26.7 


36.0 


8.26 


3 




143 


50 


oc 


n 


8/27/28 


24.5 


36.2 


8.21 


9 


23 


145 





r 


p 


8/29/28 


27.2 


35.9 


8.25 


4 




148 





r 


n 


8/29/28 


27.2 


35.9 


8.25 


4 




149 


50 


oc 


n 


8/29/28 


20.9 


36.0 


8.27 


4 


24 


151 





r 


P 


8/31/28 


27.2 


35.2 


8.32 


4 




152 


50 


r 


P 


8/31/28 


23.1 


36.0 


8.28 


4 




155 


50 


r 


n 


8/31/28 


23.1 


36.0 


8.28 


4 


25 


157 





oc 


P 


9/ 3/28 


27.5 


35.6 


8.31 


5 




158 


50 


r 


P 


9/ 3/28 


21.5 


36.0 


8.30 


4 




161 


50 


oc 


n 


9/ 3/28 


21.5 


36.0 


8.30 


4 




162 


100 


r 


n 


9/ 3/28 


14.6 


35.7 


8.22 


12 


31 


191 





r 


n 


10/ 3/28 


28.5 


34.4 


8.27 


2 




192 


50 


oc 


n 


10/ 3/28 


28.2 


35.4 


8.25 


2 




193 


100 


oc 


n 


10/ 3/28 


23.5 


36.5 


8.22 


2 


32 


194 





c 


si 


10/ 5/28 


28.0 


36.0 


8.23 


2 




194a 





oc 


P 


10/ 5/28 


28.0 


36.0 


8.23 


2 




195 


50 


c 


n 


10/ 5/28 


27.2 


35.9 


8.24 


2 




196 


100 


oc 


n 


10/ 5/28 


22.2 


36.4 


8.20 


4 


33 


197a 





oc 


P 


10/ 8/28 


28.5 


35.6 


8.23 


4 




198 


50 


r 


n 


10/ 8/28 


28.2 


36.2 


8.24 


4 




198a 


50 


oc 


p 


10/ 8/28 


28.2 


36.2 


8.24 


4 


34 


200 





oc 


n 


10/ 9/28 


28.5 


35.9 


8.28 


2 




200a 





oc 


p 


10/ 9/28 


28.5 


35.9 


8.28 


2 




201 


100 


r 


n 


10/ 9/28 


20.5 


36.6 


8.16 


16 




202 


50 


oc 


n 


10/ 9/28 


25.0 


36.5 


8.21 


3 










Pacific 










35 


205 


100 


r 


n 


10/26/28 


14.4 


34.9 


7.88 


189 




206 





oc 


P 


10/26/28 


27.4 


29.7 


8.31 


15 


35a 


208 





c 


n 


10/26/28 


(27.0) 


(30.5) 


(8.26) 


(16)* 




209 





c 


n 


10/27/28 


(27.0 


(30.5) 


(8.26) 


(16)* 




211 





oc 


n 


10/28/28 


(27.0) 


(30.5) 


(8.26) 
(8.26) 


(16)* 




212 





c 


n 


10/28/28 


(27.0^ 


(30.5) 


(16)* 


36 


213 





oc 


n 


10/20/28 


26.5 


31.6 


8.23 


16 




216 





r 


P 


10/20/28 


26.5 


31.6 


8.23 


16 


37 


217 





oc 


n 


11/ 1/28 


27.1 


31.7 


8.28 


15 




218 


50 


oc 


n 


11/ 1/28 


19.8 


34.5 


8.00 


121 




219 


100 


oc 


n 


11/ 1/28 


15.1 


34.9 


7.92 


153 




220 





oc 


P 


11/ 1/28 


27.1 


31.7 


8.28 


15 


38 


222 





r 


n 


11/ 3/28 


26.5 


32.9 


8.33 


20 


39 


226 


50 


r 


n 


11/ 6/28 


16.3 


34.6 


7.92 


48 




227 


100 


r 


n 


11/ 6/28 


14.0 


35.0 


7.88 


181 


41a 


240 





oc 


n 


11/12/28 


(21.0) 


(34.0) 


(8.15) 


(28)* 


42 


241 





r 


n 


11/13/28 


18.7 


34.7 


8.10 


45 




243 


100 


r 


n 


11/13/28 


13.6 


35.0 


7.91 


150 


44 


250 





r 


n 


11/17/28 


20.7 


34.9 


8.03 


38 


45 


256 





oc 


n 


11/19/28 


22.4 


35.3 


8.12 


38 




257 


50 


oc 


n 


11/19/28 


22.4 


35.2 


8.13 


46 




258 


100 


r 


n 


11/19/28 


18.6 


35.1 


8.12 


46 




259 





r 


P 


11/19/28 


22.4 


35.3 


8.12 


38 




260 


50-0 


r 


p 


11/19/28 


22.4 


35.3 


8.12 


38 




261 





oc 


n 


11/21/28 


23.3 


35.3 


8.16 


36 




262 


50 


oc 


n 


11/21/28 


23.2 


35.3 


8.16 


40 




263 


100 


r 


n 


11/21/28 


22.6 


35.4 


8.17 


40 




264 





r 


p 


11/21/28 


23.3 


35,3 


8,16 


36 


47 


266 





r 


n 


11/23/28 


23.9 


36.0 


8.23 


17 




267 


50 


oc 


n 


11/23/28 


23.8 


36.0 


8.23 


20 




268 


100 


r 


n 


11/23/28 


22.7 


36.2 


8.23 


20 




270 


50 


r 


p 


11/23/28 


23.8 


36.0 


8.23 


20 


48 


271 





oc 


n 


11/25/28 


23.6 


36.4 


8.23 


13 




272 


50 


oc 


n 


11/25/28 


23.6 


36.4 


8.24 


16 




273 


100 


oc 


n 


11/25/28 


22.7 


36.3 


8.26 


16 



70 STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Table 12. Distributional and environmental records for 


Ceratocorys horrida Stein- -Continued 


Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 


Salinity 
(o/oo) 


PH 


p 04, 

mg/ra 3 











Pacifi 


c --Continued 
11/25/28 










48 


274 





oc 


p 


23.6 


36.4 


8.23 


13 


49 


277 





oc 


n 


11/27/28 


23.4 


36.2 


8.27 


13 




278 


50 


oc 


n 


11/27/28 


22.6 


36.1 


8.26 


13 




279 


100 


oc 


n 


11/27/28 


21.6 


35.9 


8.26 


13 




281 


50 


r 


P 


11/27/28 


22.6 


36.1 


8.26 


13 


49a 


283 





oc 


n 


11/28/28 (23.3) 


(36.1) 


(8.25) 


(13)* 


50 


284 





oc 


n 


11/29/28 


23.2 


36.0 


8.23 


13 




285 


50 


oc 


n 


11/29/28 


22.0 


36.0 


8.23 


13 




288 


50 


r 


P 


11/29/28 


22.0 


36.0 


8.23 


13 


50a 


290 





oc 


n 


11/30/28 ( 


23.0) 


(35.8) 


(8.22) 


(13)* 




291 





oc 


n 


11/30/28 1 


23.0) 


(35.8) 


(8.22) 


(13)* 




292 





oc 


n 


11/30/28 ( 


23.0) 


(35.8) 


(8.22) 


(13)* 


51 


293 





oc 


n 


12/ 1/28 


22.8 


35.6 


8.22 


16 




294 


50 


oc 


n 


12/ 1/28 


20.5 


35.6 


8.22 


16 




295 


100 


oc 


n 


12/ 1/28 


20.0 


35.6 


8.22 


17 


52 


299 





r 


n 


12/ 3/28 


22.5 


35.4 


8.21 


8 




300 


50 


oc 


n 


12/ 3/28 


20.2 


35.6 


8.20 


8 




301 


100 


oc 


n 


12/ 3/28 


18.2 


35.2 


8.17 


8 


53 


303 





r 


n 


12/ 5/28 


22.6 


35.7 


8.22 


13 




304 


50 


oc 


n 


12/ 5/28 


21.2 


35.8 


8.20 


13 




305 


100 


c 


n 


12/ 5/28 


19.9 


35.6 


8.20 


13 




306 





oc 


P 


12/ 5/28 


22.6 


35.7 


8.22 


13 


53a 


307 





oc 


n 


12/ 6/28 ( 


23.0) 


(35.6) 


(8.22) 


(11)* 




308 





oc 


n 


12/ 6/28 i 


23.0) 


(35.6) 


(8.22) 


(11)* 




310 





c 


n 


12/10/28 I 


23.0) 


(35.6) 


(8.22) 


(11)* 




311 





oc 


n 


12/10/28 


23.0) 


(35.6) 


8.22 


(11)* 




312 





oc 


n 


12/10/28 


23.0) 


(35.6) 


(8.22) 


(11)* 




313 





r 


n 


12/10/28 


,23.0) 


(35.6) 


(8.22) 


(11 J* 




316 





r 


n 


12/12/28 


23.0) 


(35.6) 


(8.22) 


(11)* 




317 





oc 


n 


12/12/28 


[23.0) 


(35.6) 


(8.22) 


(11)* 


54 


320 


50 


oc 


n 


12/14/28 


19.8 


35.4 


8.18 


17 




321 


100 


oc 


n 


12/14/28 


18.7 


35.4 


8.16 


20 




322 





oc 


P 


12/14/28 


23.4 


35.5 


8.22 


9 


55 


323 





r 


n 


12/16/28 


20.4 


34.9 


8.19 


12 




324 


50 


oc 


n 


12/16/28 


18.7 


35.0 


8.18 


12 




325 


100 


oc 


n 


12/16/28 


16.7 


34.9 


7.17 


12 




327 


50 


r 


p 


12/16/28 


18.7 


35.0 


8.18 


12 


56 


328 





oc 


n 


12/18/28 


20.8 


34.9 


8.13 


9 




329 


50 


oc 


n 


12/18/28 


18.5 


35.1 


8.14 


9 




330 


100 


r 


n 


12/18/28 


16.6 


34.8 


8.11 


12 




331 





r 


p 


12/18/28 


20.8 


34.9 


8.13 


9 




332 


50 


r 


p 


12/18/28 


18.5 


35.1 


8.14 


9 




333 


100 


r 


p 


12/18/28 


16.6 


34.8 


8.11 


12 


56a 


334 





r 


n 


12/19/28 


(20.0) 


(34.9) 


(8.13) 


(15/* 


57 


335 





oc 


n 


12/20/28 


19.0 


34.5 


8.14 


20 




336 


50 


oc 


n 


12/20/28 


15.6 


34.3 


8.14 


21 




337 


100 


r 


n 


12/20/28 


14.3 


34.4 


8.13 


25 




338 





r 


p 


12/20/28 


19.0 


34.5 


8.14 


20 


61a 


369 





r 


n 


12/28/28 


(17.5) 


(34.1) 


(8.07) 


(39)* 


75 


462 





r 


n 


2/14/29 


22.8 


35.8 


8.18 


44 




465 





r 


p 


2/14/29 


22.8 


35.8 


8.18 


44 


76 


467 





c 


n 


2/16/29 


23.4 


35.9 


8.15 


50 




469 


100 


r 


n 


2/16/29 


21.2 


35.8 


8.12 


50 




470 





r 


p 


2/16/29 


23.4 


35.9 


8.15 


50 


77 


472 





oc 


n 


2/18/29 


23.7 


36.0 


8.19 


16 




473 





r 


p 


2/18/29 


23.7 


36.0 


8.19 


16 




474 


50 


oc 


p 


2/18/29 


23.5 


36.0 


8.19 


16 


78 


475 





r 


n 


2/20/29 


24.6 


36.0 


8.2 


32 




477 


100 


oc 


n 


2/20/29 


21.9 


36.2 


8.1 


34 




478 





r 


p 


2/20/29 


24.6 


36.0 


8.2 


32 


79 


481 





oc 


n 


2/22/29 


25.2 


36.0 


8.17 


34 




482 





r 


n 


2/22/29 


25.2 


36.0 


8.17 


34 




483 


100 


oc 


n 


2/22/29 


21.8 


36.2 


8.13 


45 




484 





r 


p 


2/22/29 


25.2 


36.0 


8.17 


34 


80 


486 





r 


n 


2/24/29 


26.0 


35.9 


8.20 


36 




487 


50 


r 


n 


2/24/29 


25.9 


36.0 


8.19 


29 




488 





r 


p 


2.24/29 


26.0 


35.9 


8.20 


36 




489 


50 


r 


p 


2/24/29 


25.9 


36.0 


8.19 


29 


81 


491 





oc 


n 


2/26/29 


26.5 


35.8 


8.19 


38 




492 


50 


r 


n 


2/26/29 


26.4 


35.9 


8.19 


38 




495 


100 


r 


p 


2/26/29 


23.7 


36.2 


8.18 


36 


82 


496 





oc 


n 


2/28/29 


27.2 


36.3 


8.21 


34 




497 


50 


r 


n 


2/28/29 


27.2 


36.3 


8.21 


34 


83 


501 





oc 


n 


3/ 2/29 


27.5 


36.3 


8.24 


29 




502 


50 


oc 


n 


3/ 2/29 


27.5 


36.5 


8.24 


25 




504 


50 


r 


D 


3/ 2/29 


27.5 


36.5 


8.24 


25 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



71 



Table 12. Distributional and environmental records for Ceratocorys horrida Stein--Continued 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 

(°C) 



Salinity 
(o/oo) 



PH 



P °/ 4 3 

mg/m° 











Pacific 


--Continued 










84 


505 





r 


n 


3/ 4/29 


27.8 


36.2 


8.23 


24 




506 


50 


r 


n 


3/ 4/29 


27.5 


36.4 


8.21 


24 


85 


510 





r 


n 


3/ 6/29 


27.9 


36.2 


8.22 


40 




511 


50 


r 


n 


3/ 6/29 


27.9 


36.2 


8.22 


40 


86 


515 





oc 


n 


3/ 9/29 


28.2 


36.2 


8.29 


20 




516 





c 


n 


3/ 9/29 


28.2 


36.2 


8.29 


20 




517 


50 


oc 


n 


3/ 9/29 


27.5 


36.2 


8.29 


17 




518 





r 


P 


3/ 9/29 


28.2 


36.2 


8.29 


20 


87 


521 





c 


n 


3/11/29 


27.9 


36.1 


8.28 


17 




522 


50 


oc 


n 


3/11/29 


26.5 


36.1 


8.26 


20 




523 





r 


P 


3/11/29 


27.9 


36.1 


8.28 


17 




524 


50 


r 


P 


3/11/29 


26.5 


36.1 


8.26 


20 


88 


526 





oc 


n 


3/21/29 


28.5 


35.9 


8.23 


16 




527 


50 


oc 


n 


3/21/29 


28.5 


35.9 


8.25 


13 


89 


528 





oc 


n 


3/23/29 


28.4 


35.6 


8.25 


21 




529 


50 


r 


n 


3/23/29 


28.6 


35.8 


8.27 


12 




530 





r 


P 


3/23/29 


28.4 


35.6 


8.25 


21 




532 





oc 


n 


3/23/29 


28.4 


35.6 


8.25 


21 


90 


533 





c 


n 


3/25/29 


28.5 


35.5 


8.27 


21 




534 


50 


oc 


n 


3/25/29 


28.6 


35.6 


8.26 


21 


91 


540 





oc 


n 


3/27/29 


28.7 


35.1 


8.30 


21 




541 


50 


oc 


n 


3/27/29 


28.5 


35.2 


8.30 


24 




542 





r 


P 


3/27/29 


28.7 


35.1 


8.30 


21 




544 


100 


r 


P 


3/27/29 


25.8 


36.0 


8.25 


30 


92 


545 





c 


n 


3/29/29 


28.5 


35.3 


8.29 


28 




546 


50 


oc 


n 


3/29/29 


28.4 


35.4 


8.29 


28 


93 


550 





c 


n 


3/31/29 


28.7 


34.7 


8.30 


28 




551 


50 


oc 


n 


3/31/29 


28.5 


34.8 


8.30 


28 




552 





r 


P 


3/31/29 


28.7 


34.7 


8.30 


28 




553 


100 


r 


P 


3/31/29 


27.6 


35.9 


8.27 


29 


94 


557 





r 


n 


4/22/29 


29.5 


34.7 


8.25 


14 




558 


50 


oc 


n 


4/22/29 


29.3 


34.7 


8.25 


14 




559 


100 


r 


n 


4/22/29 


28.5 


35.6 


8.21 


25 


95 


563 


50 


c 


n 


4/25/29 


29.3 


34.9 


8.24 


16 




564 


100 


oc 


n 


4/25/29 


28.5 


35.4 


8.22 


21 




565 





r 


p 


4/25/29 


29.4 


34.7 


8.26 


14 




567 


100 


r 


P 


4/25/29 


28.5 


35.4 


8.22 


21 




568a 





r 


n 


4/25/29 


28.5 


35.4 


8.26 


21 


96 


568 





oc 


n 


4/26/29 


29.3 


35.3 


8.23 


12 




569 


50 


oc 


n 


4/26/29 


29.2 


35.3 


8.23 


12 




570 


100 


oc 


n 


4/26/29 


28.3 


35.7 


8.19 


25 




572 


50 


r 


p 


4/26/29 


29.2 


35.3 


8.23 


12 


97 


574 





c 


n 


4/28/29 


28.3 


35.2 


8.16 


24 




575 


50 


c 


n 


4/28/29 


28.0 


35.4 


8.16 


21 




576 


100 


r 


n 


4/28/29 


27.6 


35.6 


8.15 


25 




578 


50 


r 


P 


4/28/29 


28.0 


35.4 


8.16 


21 


99 


589 





oc 


n 


5/ 2/29 


27.9 


34.9 


8.21 


12 




590 


50 


oc 


n 


5/ 2/29 


27.9 


34.9 


8.22 


12 




591 


100 


oc 


n 


5/ 2/29 


27.8 


35.0 


8.22 


17 




595 





r 


n 


5/ 2/29 


27.9 


34.9 


8.21 


12 


100 


596 


50 


c 


n 


5/ 4/29 


27.6 


34.7 


8.21 


10 




597 


100 


r 


n 


5/ 4/29 


27.6 


34.7 


8.22 


12 




599 


50 


oc 


P 


5/ 4/29 


27.6 


34.7 


8.21 


10 


101 


603 





c 


n 


5/ 7/29 


26.3 


34.7 


8.24 


8 




604 


50 


c 


n 


5/ 7/29 


26.2 


34.7 


8.24 


8 




605 


100 


c 


n 


5/ 7/29 


25.2 


35.1 


8.23 


8 




607 


50 


r 


P 


5/ 7/29 


26.2 


34.7 


8.24 


8 




608 


100 


r 


P 


5/ 7/29 


25.2 


35.1 


8.23 


8 


102 


609 





oc 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




610 


50 


oc 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




611 


100 


oc 


n 


5/ 9/29 


25.6 


35.0 


8.23 


8 


103 


615 





c 


n 


5/11/29 


26.0 


35.0 


8.25 


5 




616 


50 


c 


n 


5/11/29 


25.8 


35.2 


8.25 


5 




617 


100 


oc 


n 


5/11/29 


24.8 


35.2 


8.25 


5 




620 


100 


r 


P 


5/11/29 


24.8 


35.2 


8.25 


5 


104 


621 





c 


n 


5/13/29 


26.1 


35.2 


8.24 


7 




622 


50 


c 


n 


5/13/29 


25.8 


35.2 


8.24 


7 




623 


100 


c 


n 


5/13/29 


25.3 


35.3 


8.21 


7 




624 





oc 


P 


5/13/29 


26.1 


35.2 


8.24 


7 


105 


627 


50 


c 


n 


5/15/29 


26.8 


34.9 


8.23 


5 




628 


50 


c 


n 


5/15/29 


26.8 


34.9 


8.23 


5 




629 


100 


c 


n 


5/15/29 


25.2 


35.1 


8.23 


5 




630 





r 


P 


5/15/29 


26.9 


34.9 


8.23 


5 


106 


633 





oc 


n 


5/1 7/29 


27.2 


35.0 


8.23 


5 




634 


50 


oc 


n 


5/17/29 


27.0 


35.0 


8.23 


5 




635 


100 


oc 


n 


5/17/29 


25.6 


35.1 


8.23 


5 



72 STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Table 12. Distributional and environmental records for Ceratocorys horrida Stein — Continued 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

(°C) 


Salinity 
(o/oo) 


pH 


p 04 

mg/m 3 










Pacific 


--Continued 








107 


639 





c 


n 


5/19/29 


28.0 


34.4 


8.23 


5 




640 


50 


oc 


n 


5/19/29 


27.9 


34.4 


8.23 


4 


108 


646 





c 


n 


5/27/29 


28.4 


35.0 


8.25 


4 




647 


50 


oc 


n 


5/27/29 


26.8 


35.0 


8.24 


4 




648 


100 


c 


n 


5/27/29 


25.2 


35.0 


8.23 


4 


Guam 


652 





r 


n 


May 1929 

5/29/29 










109 


654 





c 


n 


27.4 


35.0 


8.23 


3 




655 


50 


oc 


n 


5/29/29 


23.1 


35.0 


8.22 


3 




656 


100 


oc 


n 


5/29/29 


19.4 


34.8 


8.18 


5 




658 


50 


oc 


P 


5/29/29 


23.1 


35.0 


8.22 


3 




659 


100 


oc 


P 


5/29/29 


19.4 


34.8 


8.18 


5 




660 





oc 


P 


5/29/29 


27.4 


35.0 


8.23 


3 


110 


661 





oc 


n 


5/31/29 


23.9 


34.7 


8.18 


5 




662 


50 


oc 


n 


5/31/29 


18.4 


34.8 


8.16 


5 




663 


100 


r 


n 


5/31/29 


17.9 


34.7 


8.14 


11 


111 


668 





r 


n 


6/ 3/29 


20.1 


34.5 


8.18 


5 




672 


50 


r 


P 


6/ 3/29 


19.4 


34.6 


8.17 


5 


112 


674 





r 


n 


6/ 5/29 


23.2 


34.6 


8.22 


7 




675 


50 


r 


n 


6/ 5/29 


21.7 


34.6 


8.23 


7 




676 


100 


r 


n 


6/ 5/29 


19.8 


34.7 


8.20 


8 


113 


680 





oc 


n 


6/25/29 


24.2 


34.5 


8.25 


5 




681 


50 


r 


n 


6/25/29 


23.8 


34.6 


8.25 


5 




682 


100 


r 


n 


6/25/29 


21.5 


34.7 


8.23 


8 




685 


100 


r 


P 


6/25/29 


21.5 


34.7 


8.23 


8 


131 


787 





r 


n 


9/ 6/29 


19.3 


33.4 


8.34 






789 


100 


r 


n 


9/ 6/29 


12.1 


33.4 


8.32 




132 


797 





oc 


n 


9/ 8/29 


21.0 


33.9 


8.34 


15* 




798 


50 


oc 


n 


9/ 8/29 


17.6 


33.9 


8.33 


19 




799 


100 


oc 


n 


9/ 8/29 


14.3 


33.4 


8.30 


16 




802 


50 


r 


P 


9/ 8/29 


17.6 


33.9 


8.33 


19 




803 


100 


r 


p 


9/ 8/29 


14.3 


33.4 


8.30 


16 


133 


804 





oc 


n 


9/10/29 


22.7 


34.7 


8.47 


7 




805 


50 


r 


n 


9/10/29 


20.8 


34.7 


8.37 


7 




806 


100 


oc 


n 


9/10/29 


18.4 


34.8 


8.31 


7 




813 


50 


r 


p 


9/10/29 


20.8 


34.7 


8.37 


7 




814 


100 


r 


P 


9/10/29 


18.4 


34.8 


8.31 


7 


134 


808 





oc 


n 


9/12/29 


22.9 


34.7 


8.34 


6 




809 


50 


oc 


n 


9/12/29 


19.8 


34.6 


8.34 


6 




810 


100 


r 


n 


9/12/29 


18.1 


34.6 


8.34 


6 




815 





r 


P 


9/12/29 


22.9 


34.7 


8.34 


6 




816 


50 


r 


P 


9/12/29 


19.8 


34.6 


8.34 


6 




817 


100 


r 


P 


9/12/29 


18.1 


34.6 


8.34 


6 


135 


820 





r 


n 


9/14/29 


23.8 


35.1 


8.37 


7 




821 


50 


r 


n 


9/14/29 


21.5 


35.0 


8.4 


5 




822 


100 


r 


n 


9/14/29 


18.7 


34.8 


8.37 


5 


136 


827 





oc 


n 


9/16/29 


24.6 


35.4 


8.37 


3 




828 


50 


oc 


n 


9/16/29 


21.4 


35.1 


8.39 


3 




829 


100 


oc 


n 


9/16/29 


18.6 


35.0 


8.39 


3 




832 





r 


p 


9/16/29 


24.6 


35.4 


8.37 


3 




834 


100 


r 


p 


9/16/29 


18.6 


35.0 


8.39 


3 


137 


836 





c 


n 


9/18/29 


25.5 


35.0 


8.39 


4 




838 


100 


r 


n 


9/18/29 


21.5 


35.1 


8.30 


5 


138 


843 





oc 


n 


9/20/29 


26.1 


34.8 


8.35 


5 




844 


50 


oc 


n 


9/20/29 


25.6 


34.7 


8.30 


3 




847 





r 


p 


9/20/29 


26.1 


34.8 


8.35 


5 


139 


849 





r 


n 


9/22/29 


26.7 


34.8 


8.34 


6 




850 


50 


oc 


n 


9/22/29 


25.8 


34.9 


8.31 


6 




851 


100 


oc 


n 


9/22/29 


22.4 


35.2 


8.28 


6 




853 





r 


P 


9/22/29 


26.1 


34.9 


8.4 


5 




854 


50 


r 


p 


9/22/29 


25.8 


34.9 


8.3 


6 


140 


856 





oc 


n 


10/ 3/29 


26.9 


35.0 


8.42 


7 




857 


50 


oc 


n 


10/ 3/29 


26.9 


35.0 


8.39 


7 


858 


858 


100 


oc 


n 


10/ 3/29 


25.5 


35.0 


8.34 


7 




860 





r 


p 


10/ 3/29 


26.9 


35.0 


8.42 


7 


141 


864 





c 


n 


10/ 5/29 


25.9 


35.2 


8.34 


5 




865 


50 


c 


n 


10/ 5/2S 


24.8 


35.3 


8.34 


5 




868 





r 


p 


10/ 5/2S 


26.9 


35.2 


8.34 


5 




869 


50 


r 


p 


10/ 5/28 


24.8 


35.3 


8.34 


5 




870 


50 


r 


p 


10/ 5/28 


24.8 


35.3 


8.34 


5 


142 


872 





c 


n 


10/ 7/28 


24.1 


34.8 


8.33 


5 




873 


50 


oc 


n 


10/ 7/28 


21.8 


34.8 


8.30 


5 




874 


100 


c 


n 


10/ 7/2S 


16.6 


34.4 


8.27 


7 




876 





r 


p 


10/ 7/28 


24.1 


34.8 


8.33 


5 




877 


50 


r 


p 


10/ 7/2S 


21.8 


34.8 


8.30 


5 




879 


100 


r 


p 


10/ 7/28 


16.6 


34.4 


8.27 


7 


143 


883 


100 


r 


n 


10/ 9/28 


13.8 


34.1 


8.30 


10 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



73 



Table 12. Distributional and environmental records for Ceratocorys horrida Stein- -Concluded 



Station 



Sample 



Depth 

(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 
(°C) 



Salinity 
(o/oo) 



PH 



p 04 „ 
mg/m3 











Pacific 


--Concluded 










144 


886 





oc 


n 


10/11/29 


23.3 


35.0 


8.37 


6 


145 


890 





oc 


n 


10/13/29 


22.3 


34.6 


8.29 


6 




891 


50 


oc 


n 


10/13/29 


18.7 


34.3 


8.34 


6 




892 


100 


oc 


n 


10/13/29 


16.0 


34.1 


8.31 


G 


146 


896 





oc 


n 


10/15/29 


22.4 


34.9 


8.37 


6 




897 


50 


oc 


n 


10/15/29 


22.4 


34.9 


8.30 


6 




898 


100 


oc 


n 


10/15/29 


19.7 


34.3 


8.26 


7 


147 


904 


50 


r 


n 


10/17/29 


23.1 


35.3 


8.29 


5 




905 


100 


oc 


n 


10/17/29 


19.2 


35.0 


8.29 


5 


148 


910 





oc 


n 


10/19/29 


23.4 


35.2 








912 


100 


r 


n 


10/19/29 


20.0 


35.0 






149 


920 





oc 


n 


10/21/29 


23.5 


35.0 


8.34 


' *6 




921 


50 


oc 


n 


10/21/29 


23.3 


35.0 


8.37 


6 




922 


100 


oc 


n 


10/21/29 


20.3 


34.9 


8.38 


6 


150 


929 





oc 


n 


10/23/29 


25.6 


34.7 


8.39 


7 




930 


50 


oc 


n 


10/23/29 


22.8 


34.8 


8.35 


10 




931 


100 


r 


n 


10/23/29 


19.6 


34.6 


8.32 


11 




936 


100 


r 


P 


10/23/29 


19.6 


34.6 


8.32 


11 


151 


937 





r 


n 


10/25/29 


26.0 


34.0 








938 


50 


r 


n 


10/25/29 


18.3 


34.4 








939 


100 


r 


n 


10/25/29 


12.5 


34.6 






152 


944 





r 


n 


10/27/29 


27.4 


33.7 


8.35 


20 




946 


100 


r 


n 


10/27/29 


11.4 


34.7 


7.76 


75 


153 


951 





oc 


n 


10/29/29 


28.1 


34.2 


8.47 


7 




952 


50 


oc 


n 


10/29/29 


28.1 


34.4 


8.39 


7 




953 


100 


r 


n 


10/29/29 


20.5 


34.7 


8.28 


31 




955 





r 


p 


10/29/29 


28.1 


34.2 


8.47 


7 


154 


958 





oc 


n 


10/31/29 


28.3 


34.2 


8.39 


7 




959 


50 


oc 


n 


10/31/29 


28.2 


34.2 


8.40 


7 


155 


965 





c 


n 


11/ 2/29 


27.8 


34.9 


8.29 


29 




966 


50 


oc 


n 


11/ 2/29 


27.7 


34.9 


8.30 


30 




967 


100 


oc 


n 


11/ 2/29 


27.2 


35.0 


8.30 


35 


156 


972 





oc 


n 


11/ 4/29 


27.6 


35.0 


8.34 


28 




973 


50 


r 


n 


11/ 4/29 


27.0 


35.1 


8.37 


46 




974 


100 


oc 


n 


11/ 4/29 


26.4 


35.1 


8.30 


48 


157 


978 





c 


n 


11/ 6/29 


27.1 


35.3 


8.27 


47 




979 


50 


c 


n 


11/ 6/29 


27.1 


35.2 


8.32 


60 




980 


100 


oc 


n 


11/ 6/29 


26.9 


35.5 


8.30 


64 


158 


983 





c 


n 


11/ 8/29 


28.2 


35.6 


8.34 


36 




984 


50 


c 


n 


11/ 8/29 


28.2 


35.6 


8.39 


50 




985 


100 


c 


n 


11/ 8/29 


27.6 


35.9 


8.39 


48 


159 


990 





oc 


n 


11/11/29 


28.6 


35.7 


8,37 


15 




991 


50 


oc 


n 


11/11/29 


28.5 


35.7 


8.39 


15 




992 


100 


r 


a 


11/11/29 


28.0 


35.7 


8.37 


23 


160 


1000 





r 


n 


11/13/29 


28.6 


35.6 


8.37 


12 




1002 


50 


r 


n 


11/13/29 


28.6 


35.6 


8.39 


15 



Table 13. Distributional and environmental records for Ceratocorys armata (Sehutt) Kofoid 



Station 


Sampie 


Depth 

(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

(°C) 


Salinity 
(o/oo) 


pH 


P ? 4 3 

mg/m° 










AtlE 


intic 










2 


13 


100 


r 


n 


5/18/28 


19.8 


36.4 


8.21 


33 




14 





r 


n 


5/18/28 


20.5 


36.4 


8.23 


58 


15 


99 


100 


r 


P 


8/11/28 


18.4 


36.4 


8.20 


19 


16 


103 





r 


P 


8/13/28 


25.9 


36.2 


8.24 


8 




104 


50 


r 


P 


8/13/28 


24.4 


36.4 


8.23 


8 




106 





oc 


n 


8/13/28 


25.9 


36.2 


8.24 


8 


18 


114 





r 


P 


8/17/28 


27.0 


37.0 


8.23 


5 




115 


50 


r 


P 


8/17/28 


22.4 


36.8 


8.24 


5 




117 





c 


n 


8/17/28 


27.0 


37.0 


8.23 


5 




118 


50 


r 


n 


8/17/28 


22.4 


36.8 


8.24 


5 




119 


100 


oc 


n 


8/17/28 


20.4 


36.8 


8.24 


5 


21 


134 


100 


oc 


P 


8/25/28 


21.0 


36.8 


8.25 


4 




135 





oc 


n 


8/25/28 


26.6 


36.3 


8.32 


4 


22 


139 





r 


P 


8/27/28 


26.7 


36.0 


8.26 


8 




140 


50 


r 


P 


8/27/28 


24.5 


36.2 


8.21 


9 


24 


151 





r 


P 


8/31/28 


27.2 


35.2 


8.32 


4 


25 


157 





r 


P 


9/ 3/28 


27.5 


35.6 


8.31 


5 


28 


178 


100 


r 


n 


9/11/28 


22.8 


36.6 


8.23 


4 


29 


184 


100 


r 


n 


9/13/28 


23.1 


36.6 


8.26 


8 


31 


191 





r 


n 


10/ 3/28 


28.5 


34.4 


8.27 


2 


34 


200 





r 


n 


10/ 9/28 


28.5 


35.9 


8.28 


2 




200a 





oc 


P 


10/ 9/28 


28.5 


35.9 


8.28 


■2 



74 STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Table 13. Distributional and environmental records for Ceratocorys armata (Schutt) Kofoid- -Continued 



Station 



Sample 



Depth 

(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 
(°C) 



Salinity 
(o/oo) 



PH 



p 04 

mg/m 3 











p 


acif ic 










35a 


209 





r 


n 


10/27/28 


(27.0) 


(30.0) 


(8.26) 


(15)* 


36 


213 





r 


n 


10/20/28 


26.5 


31.6 


8.23 


16 




215 


100 


r 


n 


10/20/28 


14.4 


34.9 


7.8 


149 


41 


237 


100 


r 


n 


11/10/28 


14.5 


35.0 


7.92 


151 




238 





r 


P 


11/10/28 


20.4 


34.2 


8.11 


32 




239 


100 


r 


P 


11/10/28 


14.5 


35.0 


7.92 


151 


48 


272 


50 


oc 


n 


11/25/28 


23.6 


36.4 


8.24 


16 




273 


100 


oc 


n 


11/25/28 


22.7 


36.3 


8.26 


16 




274 





r 


P 


11/25/28 


23.6 


36.4 


8.23 


13 




275 


50 


r 


P 


11/25/28 


23.6 


36.4 


8.24 


16 


49 


277 





oc 


n 


11/27/28 


23.4 


36.2 


8.27 


13 




279 


100 


oc 


n 


11/27/28 


21.6 


35.9 


8.26 


13 




280 





r 


P 


11/27/28 


23.4 


36.2 


8.27 


13 


49a 


283 





oc 


n 


11/28/28 


(23.3) 


(36.1) 


(8.25) 


(13)* 


50 


284 





c 


n 


11/29/28 


23.2 


36.0 


8.23 


13 




285 


50 


oc 


n 


11/29/28 


22.0 


36.0 


8.23 


13 




286 


100 


oc 


n 


11/29/28 


20.5 


35.7 


8.22 


13 




287 





oc 


p 


11/29/28 


23.2 


36.0 


8.23 


13 


50a 


290 





oc 


n 


11/30/28 


(23.0) 


(35.8) 


(8.22) 
(8.22) 


88: 




291 





oc 


n 


11/30/28 


(23.0) 


(35.8) 




292 





oc 


n 


11/30/28 


(23.0) 


(35.8) 


(8.22) 


(13)* 


51 


294 


50 


oc 


n 


12/ 1/28 


20.5 


35.6 


8.22 


16 




295 


100 


oc 


n 


12/ 1/28 


20.0 


35.6 


8.22 


17 




296 





r 


P 


12/ 1/28 


22.8 


35.6 


8.22 


16 


52 


300 


50 


oc 


n 


12/ 3/28 


20.2 


35.6 


8.20 


8 




301 


100 


oc 


n 


12/ 3/28 


18.2 


35.2 


8.17 


8 




302 





oc 


P 


12/ 3/28 


22.5 


35.4 


8.21 


8 


53 


304 


50 


c 


n 


12/ 5/28 


21.2 


35.8 


8.20 


13 




305 


100 


oc 


n 


12/ 5/28 


19.9 


35.6 


8.20 


13 




306 





r 


p 


12/ 5/28 


22.6 


35.7 


8.22 


13 


53a 


308 





r 


n 


12/ 6/28 


(23.0) 


(35.6) 


(8.22) 


(11)* 




310 





c 


n 


12/10/28 


23.0) 


(35.6) 


(8.22 


(11)* 




311 





oc 


n 


12/10/28 


(23.0) 


35.6) 


(8.22) 


(11 * 




312 





oc 


n 


12/10/28 


23.0) 


35.6) 


(8.22 


11* 

(11* 




313 





oc 


n 


12/10/28 


(23.0 


(35.6 


(8.22) 




316 





r 


n 


12/12/28 


(23.0 


(35.6) 


(8.22 


11* 




317 





oc 


n 


12/12/28 


(23.0) 


(35.6) 


(8.22) 


(11)* 


54 


320 


50 


r 


n 


12/14/28 


19.8 


35.4 


8.18 


17 




322 





oc 


p 


12/14/28 


23.4 


35.5 


8.22 


9 


55 


323 





r 


n 


12/16/28 


20.4 


34.9 


8.19 


12 




324 


50 


oc 


n 


12/16/28 


18.7 


35.0 


8.18 


12 




325 


50 


oc 


n 


12/16/28 


18.7 


35.0 


8.18 


12 


56 


328 





oc 


n 


12/18/28 


20.8 


34.9 


8.13 


9 




329 


50 


oc 


n 


12/18/28 


18.5 


35.1 


8.14 


9 




330 


100 


oc 


n 


12/18/28 


16.6 


34.8 


8.11 


12 




331 





oc 


p 


12/18/28 


20.8 


34.9 


8.13 


9 




332 


50 


r 


p 


12/18/28 


18.5 


35.1 


8.14 


9 


56a 


334 





oc 


n 


12/19/28 


(20.0) 


(34.9) 


(8.13) 


(15)* 


57 


336 


50 


oc 


n 


12/20/28 


15.6 


34.3 


8.14 


21 




338 





r 


p 


12/20/28 


19.0 


34.5 


8.14 


20 




339 


50 


r 


p 


12/20/28 


15.6 


34.3 


8.14 


21 




340 


100 


r 


p 


12/20/28 


14.3 


34.4 


8.13 


25 


62 


373 


100 


r 


n 


12/30/28 


13.2 


34.2 


8.06 


48 


63 


380 


50 


r 


n 


1/ 1/29 


17.0 


34.6 


8.08 


25 




382 





r 


P 


1/ 1/29 


20.5 


34.6 


8.07 


21 


64a 


401 





r 


n 


1/ 3/29 


(20.4) 


(34.6) 


(8.11) 


(22)* 


78 


478 





r 


p 


2/20/29 


24.6 


36.0 


8.17 


32 


83 


503 





r 


p 


3/ 2/29 


27.5 


36.3 


8.24 


29 


84 


506 


50 


r 


n 


3/ 4/29 


27.5 


36.4 


8.21 


24 


85 


510 





r 


n 


3/ 6/29 


28.0 


36.3 


8.22 


40 


86 


515 





r 


n 


3/ 9/29 


28.2 


36.2 


8.29 


20 




516 





oc 


n 


3/ 9/29 


28.2 


36.2 


8.29 


20 




517 


50 


r 


n 


3/ 9/29 


27.5 


36.2 


8.29 


17 




518 





r 


p 


3/ 9/29 


28.2 


36.2 


8.29 


20 


87 


521 





r 


n 


3/11/29 


27.9 


36.1 


8.28 


17 


88 


526 





oc 


n 


3/21/29 


28.5 


35.9 


8.23 


16 


89 


528 





r 


n 


3/23/29 


28.4 


35.6 


8.25 


21 




532 





r 


n 


3/23/29 


28.4 


35.6 


8.25 


21 


90 


533 





oc 


n 


3/25/29 


28.5 


35.5 


8.27 


21 




534 


50 


oc 


n 


3/25/29 


28.6 


35.6 


8.26 


21 




535 





r 


P 


3/25/29 


28.5 


35.5 


8.27 


21 


91 


540 





oc 


n 


3/27/29 


28.7 


35.1 


8.30 


21 




541 


50 


oc 


n 


3/27/29 


28.5 


35.2 


8.30 


24 




542 





r 


p 


3/27/29 


28.7 


35.1 


8.30 


21 


92 


545 





oc 


n 


3/29/29 


28.5 


35.3 


8.29 


28 


93 


550 





r 


n 


3/31/29 


28.7 


34.7 


8.30 


28 




551 


50 


oc 


n 


3/31/29 


28.5 


34.8 


8.30 


28 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



75 



Table 13. Distributional and environmental records for Ceratocorys armata (Schiitt) Kofoid- -Concluded 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

(°C) 


Salinity 
(o/oo) 


PH 


P04 

mg/m^ 










Pacific- 


--Concluded 








95 


568a 





r 


n 


4/24/29 


29.4 


34.7 


8.26 


14 


99 


595 





r 


n 


5/ 2/29 


27.9 


34.9 


8.21 


12 


101 


603 





c 


n 


5/ 7/29 


26.3 


34.7 


8.24 


8 




604 


50 


c 


n 


5/ 7/29 


26.3 


34.7 


8.24 


8 




605 


100 


c 


n 


5/ 7/29 


25.3 


35.1 


8.23 


8 




608 


100 


r 


P 


5/ 7/29 


25.3 


35.1 


8.23 


8 


102 


609 





r 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




610 


50 


oc 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




611 


100 


oc 


n 


5/ 9/29 


25.6 


35.0 


8.23 


8 




612 





r 


P 


5/ 9/29 


25.8 


35.0 


8.24 


8 




613 


50 


r 


P 


5/ 9/29 


25.8 


35.0 


8.24 


8 


103 


615 





c 


n 


5/11/29 


26.0 


35.0 


8.25 


5 




616 


50 


oc 


n 


5/11/29 


25.9 


35.2 


8.25 


5 




617 


100 


r 


n 


5/11/29 


24.8 


35.2 


8.25 


5 




620 


100 


r 


P 


5/11/29 


24.8 


35.2 


8.25 


5 


104 


621 





c 


n 


5/13/29 


26.1 


35.2 


8.24 


7 




622 


50 


oc 


n 


5/13/29 


25.9 


35.2 








623 


100 


oc 


n 


5/13/29 


26.3 


35.3 


8.21 


' '7 




624 





r 


p 


5/13/29 


26.1 


35.2 


8.24 


7 


105 


627 


50 


c 


n 


5/13/29 


25.9 


35.2 


8.24 


7 




629 


100 


oc 


n 


5/13/29 


26.3 


35.3 


8.21 


7 


106 


633 





oc 


n 


5/17/29 


27.2 


35.0 


8.23 


5 




634 


50 


oc 


n 


5/17/29 


27.0 


35.0 








635 


100 


oc 


n 


5/17/29 


25.6 


35.1 


8.23 


' V 


107 


639 





oc 


n 


5/19/29 


28.0 


34.4 


8.23 


5 




641 


100 


r 


n 


5/19/29 


26.8 


34.9 


8.23 


5 


109 


654 





oc 


n 


5/29/29 


27.4 


35.0 


8.23 


3 




655 


50 


r 


n 


5/29/29 


23.1 


35.0 








658 


50 


r 


P 


5/29/29 


23.1 


35.0 








660 





r 


p 


5/29/29 


27.4 


35.0 


8.23 


' 3 


110 


661 





r 


n 


5/31/29 


23.9 


34.7 


8.18 


5 


113 


680 





r 


n 


6/25/29 


24.2 


34.5 


8.25 


5 


134 


810 


100 


r 


n 


9/12/29 


18.1 


34.6 


8.34 


6 


135 


818 





r 


n 


9/14/29 


23.8 


35.1 


8.37 


7 




824 





r 


P 


9/14/29 


23.8 


35.1 


8.37 


7 


136 


827 





r 


n 


9/16/29 


24.6 


35.4 


8.37 


3 




829 


100 


r 


n 


9/16/29 


18.7 


35.0 


8.39 


3 




832 





r 


P 


9/16/29 


24.6 


35.4 


8.37 


3 


137 


836 





r 


n 


9/18/29 


25.5 


35.0 


8.39 


4 




838 


100 


r 


n 


9/18/29 


21.5 


35.1 


8.30 


5 




840 





r 


p 


9/18/29 


25.5 


35.0 


8.39 


4 




842 


100 


r 


P 


9/18/29 


21.5 


35.1 


8.30 


5 


138 


844 


50 


r 


n 


9/20/29 


25.6 


34.7 


8.30 


3 




845 


100 


r 


n 


9/20/29 


22.2 


34.8 


8.31 


3 


139 


850 


50 


r 


n 


9/22/29 


25.8 


34.9 


8.31 


6 


141 


864 





r 


n 


10/ 5/29 


25.9 


35.2 


8.34 


5 




870 


50 


r 


P 


10/ 5/29 


24.8 


35.3 


8.34 


5 


142 


872 





r 


n 


10/ 7/29 


24.1 


34.9 


8.33 


5 




873 


50 


r 


n 


10/ 7/29 


21.8 


34.8 


8.30 


5 




874 


100 


r 


n 


10/ 7 29 


16.6 


34.5 


8.27 


7 


144 


886 





r 


n 


10/11/29 


23.27 


35.0 


8.37 


6 




887 





r 


P 


10/11/29 


23.27 


35.0 


8.37 


6 


145 


890 





oc 


n 


10/13/29 


22.3 


34.6 


8.29 


6 




891 


50 


oc 


n 


10/13/29 


18.7 


34.3 


8.34 


6 




892 


100 


r 


n 


10/13/29 


16.0 


34.1 


8.31 


6 




893 





r 


P 


10/13/29 


22.3 


34.6 


8.29 


6 


146 


896 





r 


n 


10/15/29 


22.4 


34.9 


8.37 


6 


149 


921 


50 


r 


n 


10/21/29 


23.3 


35.0 


8.36 


6 




922 


100 


r 


n 


10/21/29 


20.3 


34.9 


8.36 


6 




927 





r 


P 


10/21/29 


23.5 


35.0 


8.34 


6 




928 


50 


r 


n 


10/21/29 


23.3 


35.0 


8.36 


6 


150 


930 


50 


oc 


n 


10/23/29 


22.9 


34.8 


8.34 


10 




931 


100 


r 


n 


10/23/29 


19.6 


34.6 


8.32 


11 


154 


959 


50 


r 


n 


10/31/29 


28.2 


34.2 


8.40 


7 



76 STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Table 14. Distributional and environmental records for Ceratocorys reticulata n.sp. 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

rc) 


Salinity 
(o/oo) 


PH 


p °4, 

mg/m 3 










Atl 


antic 










28 


177 


50 


r 


n 


9/11/28 


26.7 


36.3 


8.26 


4 










Pacific 










35b 


211 





r 


n 


10/28/28 


(27.0) 


(30.0) 


(8.27) 


(15)* 


41 


235 





r 


n 


11/10/28 


20.4 


34.2 


8.11 


32 


41a 


240 


'0 


r 


n 


11/12/28 


(19.5) 


(34.4) 


(8.09) 


(38)* 


76 


468 


50 


r 


n 


2/18/29 


22.1 


35.9 


8.14 


42 


78 


478 





r 


P 


2/20/29 


24.6 


36.0 


8.17 


32 


89 


529 


50 


r 


n 


3/23/29 


28.6 


35.8 


8.27 


12 


90 


533 





oc 


n 


3/25/29 


28.5 


35.5 


8.27 


21 




534 


50 


r 


n 


3/25/29 


28.6 


35.6 


8.26 


21 


91 


541 


50 


r 


n 


3/27/29 


28.5 


35.2 


8.30 


24 


92 


546 


50 


r 


n 


3/29/29 


28.4 


35.4 


8.29 


28 


94 


558 


50 


r 


n 


4/22/29 


29.3 


34.7 


8.25 


14 


95 


564 


100 


r 


n 


4/24/29 


28.5 


35.4 


8.22 


21 


96 


570 


100 


r 


n 


4/26/29 


28.3 


35.7 


8.19 


25 


100 


597 


100 


r 


n 


5/ 4/29 


27.6 


34.7 


8.22 


12 


101 


604 


50 


oc 


n 


5/ 7/29 


26.3 


34.7 


8.24 


8 




605 


100 


oc 


n 


5/ 7/29 


25.3 


35.1 


8.23 


8 




607 


50 


r 


P 


5/ 7/29 


26.3 


34.7 


8.24 


8 


102 


609 





r 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




610 


50 


oc 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




611 


100 


r 


n 


5/ 9/29 


25.6 


35.0 


8.23 


8 


104 


623 


100 


r 


n 


5/13/29 


25.3 


35.3 


8.21 


7 


106 


635 


100 


r 


n 


5/17/29 


25.6 


35.1 


8.23 


5 


137 


837 


50 


r 


n 


9/18/29 


24.5 


35.1 


8.34 


4 




842 


100 


r 


P 


9/18/29 


21.5 


35.1 


8.30 


5 


138 


844 


50 


r 


n 


9/20/29 


25.6 


34.7 


8.30 


3 


139 


850 


50 


oc 


n 


9/22/29 


25.8 


34.9 


8.31 


6 




851 


100 


r 


n 


9/22/29 


22.4 


35.2 


8.28 


6 


140 


856 





r 


n 


10/ 3/29 


26.9 


35.0 


8.42 


7 




857 


50 


r 


n 


10/ 3/29 


26.9 


35.0 


8.39 


7 




858 


100 


r 


n 


10/ 3/29 


25.5 


35.2 


8.34 


7 


141 


865 


50 


r 


n 


10/ 5/29 


24.8 


35.3 


8.34 


5 


153 


952 


50 


r 


n 


10/29/29 


28.1 


34.4 


8.39 


7 




953 


100 


r 


n 


10/29/29 


20.5 


34.7 


8.28 


31 


154 


958 





r 


n 


10/31/29 


28.3 


34.2 


8.39 


7 


156 


973 


50 


r 


P 


11/ 4/29 


27.0 


35.1 


8.37 


46 


157 


979 


50 


r 


n 


11/ 6/29 


27.1 


35.2 


8.32 


60 


158 


983 





r 


n 


11/ 8/29 


28.2 


35.6 


8.34 


36 




985 


100 


r 


n 


11/ 8/29 


27.7 


35.9 


8.39 


48 


159 


991 


50 


r 


n 


11/11/29 


28.5 


35.7 


8.38 


19 


160 


1002 


50 


r 


n 


11/13/29 


28.6 


35.6 


8.39 


14 



Table 15. Distributional and environmental records for Ceratocorys aultii n.sp. 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 
(°C) 


Salinity 
(o/oo) 


PH 


po 4 

mg/m3 










Pa 


cif ic 










57 


337 


100 


r 


n 1 


2/20/28 


14.3 


34.4 


8.10 


40 


62 


371 





r 


n 1 


2/30/28 


16.9 


34.0 


8.05 


46 


65 


406 


50 


r 


n 


1/ 5/29 


16.5 


34.5 


8.10 


25 




408 





r 


P 


1/ 5/29 


20.2 


34.5 


8.10 


24 




409 


50 


r 


P 


1/ 5/29 


16.5 


34.5 


8.10 


25 


83 


501 





r 


n 


3/ 2/29 


27.5 


36.3 


8.24 


29 




503 





r 


p 


3/ 2/29 


27.5 


36.3 


8.24 


29 


92 


549 


100 


r 


P 


3/29/29 


26.2 


36.0 


8.28 


28 


93 


551 


50 


r 


n 


3/31/29 


28.5 


34.8 


8.30 


28 


94 


558 


50 


r 


n 


4/22/29 


29.3 


34.7 


8.25 


14 




559 


100 


r 


n 


4/22/29 


28.5 


35.6 


8.21 


25 


95 


564 


100 


r 


n 


4/24/29 


28.5 


35.4 


8.22 


21 


104 


623 


100 


r 


n 


5/13/29 


25.3 


35.3 


8.21 


7 


105 


629 


100 


r 


n 


5/15/29 


25.2 


35.1 


8.23 


5 


107 


640 


50 


r 


n 


5/19/29 


27.9 


34.4 


8.23 


4 




642 





r 


P 


5/19/29 


28.0 


34.4 


8.23 


5 


132 


803 


100 


r 


P 


9/ 8/29 


14.3 


33.4 


8.30 


16 


133 


814 


100 


r 


P 


9/10/29 


18.4 


34.8 


8.31 


7 


136 


828 


50 


r 


n 


9/16/29 


21.4 


35.1 


8.39 


3 




829 


100 


r 


n 


9/16/29 


18.6 


35.0 


8.39 


3 


146 


898 


100 


r 


n 1 


0/15/29 


19.7 


34.3 


8.26 


7 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



77 



Table 16. Distribut 


onal and environmental 


records for Ceratocorys bipes (CI 


eve) Kofoid 


Station 


Sample 


Depth 

(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

r°c) 


Salinity 
(o/oo) 


PH 


PO4 

mg/m3 



14 



45 


257 


50 




258 


100 




260 


50-0 


46 


261 







262 


50 




265 


50 


47 


268 


100 


48 


273 


100 




276 


100 


52 


301 


100 


53 


305 


100 


56 


330 


100 


77 


474 


50 


79 


483 


100 


95 


563 


50 


98 


582 


50 




583 


100 




584 





100 


597 


100 




602 


100 


101 


605 


100 


109 


656 


100 




659 


100 


112 


676 


100 


137 


841 


50 


140 


863 


100 


151 


938 


50 


154 


960 


100 


156 


973 


50 




974 


100 


157 


979 


50 



r 

r 

r 

r 

r 

r 

r 

r 

r 

r 

r 

r 

oc 

r 

r 

r 

r 

r 

r 

r 

r 

oc 

r 

r 

r 

r 

r 

r 

r 

r 

r 



Atlantic 




n 


5/18/28 


25.7 


P 


ac if i c 




n 


11/19/28 


22.4 


n 


11/19/28 


18.6 


P 


11/19/28 




n 


11/21/28 


23.3 


n 


11/21/28 


23.2 


P 


11/21/28 


23.2 


n 


11/23/28 


22.7 


n 


11/25/28 


22.7 


P 


11/25/28 


22.7 


n 


12/ 3/28 


18.2 


n 


12/ 5/28 


19.9 


n 


12/18/28 


16.6 


P 


2/18/29 


23.5 


n 


2/22/29 


21.8 


n 


4/24/29 


29.3 


n 


4/30/29 


26.9 


n 


4/30/29 


26.7 


P 


4/30/29 


27.0 


n 


5/ 4/29 


27.6 


P 


5/ 4/29 


27.6 


n 


5/ 7/29 


25.3 


n 


5/29/29 


19.5 


P 
n 


6/ 5/29 


19.9 


P 


9/18/29 


24.5 


P 


10/ 3/29 


25.5 


n 


10/25/29 


18.3 


n 


10/31/29 


25.3 


P 


11/ 4/29 


27.0 


n 


11/ 4/29 


26.4 


n 


11/ 6/29 


27.1 



36.4 


8.23 


58 


35.2 


8.13 


46 


35.1 


8.12 


46 


35.3 


8.16 


36 


35.3 


8.16 


40 


35.3 


8.16 


40 


36.2 


8.23 


20 


36.3 


8.26 


16 


36.3 


8.26 


16 


35.2 


8.17 


8 


35.6 


8.20 


13 


34.8 


8.11 


12 


36.0 


8.19 


16 


36.2 


8.13 


45 


35 


8.24 


16 


35.3 


8.16 


28 


35.4 


8.14 


32 


35.3 


8.16 


24 


34.7 


8.22 


12 


34.7 


8.22 


12 


35.0 


8.23 


8 


34.8 


8.18 


5 


34.7 


8.20 


8 


35.1 


8.34 


4 


35.0 


8.34 


7 


34.4 






34.8 


7.93 


21 


35.1 


8.37 


4G 


35.1 


8.30 


48 


35.2 


8.32 


60 



Table 17. 


Distributional and environmental records for Ceratocorys skogsb 


ergii n 


sp. 


Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

(°C) 


Salinity 
(0/00) 


pH 


PO4 

mg/m3 



49a 


283 





50a 


291 





53a 


317 





85 


513 


50 


89 


529 


50 


91 


540 







542 





100 


597 


100 


102 


610 


50 


113 


682 


100 


160 


1002 


50 



P 


acif i c 




n 


11/28/28 


(23.2) 


n 


11/30/28 


22.8) 


n 


12/12/28 


(23.0) 


P 


3/ 6/29 


27.8 


n 


3/23/29 


28.6 


n 


3/27/29 


28.7 


P 


3/27/29 


28.7 


n 


5/ 4/29 


27.6 


n 


5/ 9/29 


25.8 


n 


6/25/29 


21.5 


n 


11/13/29 


28.6 



(36.0) 


(8.23) 


(13' 


35.6 


(8.22) 


(16 


(35.6) 


(8.22) 


(11 


36.2 


8.22 


40 


35.8 


8.27 


12 


35.1 


8.30 


21 


35.1 


8.30 


21 


34.7 


8.22 


12 


35.0 


8.24 


8 


34.7 


8.23 


8 


35.6 


8.39 


15 



Table 18. Distributional and environmental records for Ceratocory 


s gourretii Paulsen 


Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

( C) 


Salinity 
(0/00) 


pH 


P °/ 4 3 

mg/m° 



16 


103 





23 


145 





25 


157 





26 


163 





29 


179 







181 


100 


45 


256 







257 


50 



r 

oc 

oc 

r 

r 

r 





Atlantic 




p 


8/13/28 


25.9 


p 


8/29/28 


27.2 


p 


9/ 3/28 


27.5 


P 


9/ 5/28 


27.6 


P 


9/13/28 


27.6 


p 


9/13/28 
Pacific 


23.1 


n 


11/19/28 


22.4 


n 


11/19/28 


22.4 



36.2 


8.24 


8 


35.9 


8.25 


4 


35.6 


8.31 


5 


36.0 


8.30 


5 


36.2 


8.31 


3 


36.6 


8.26 


8 


35.3 


8.12 


38 


35.2 


8.13 


46 



8 (frag- 
ment) 



78 STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Table 18. Distributional and environmental records for Ceratocorys gourretii Paulsen--Concluded 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 
- (°C) 



Salinity 
(o/oo) 



PH 



PO4, 

mg/m 3 











Pacific 


--Concluded 












258 


100 


oc 


n 


11/19/28 


18.6 


35.1 


8.12 


46 




259 





r 


P 


11/19/28 


22.4 


35.3 


8.12 


38 




260 


50-0 


r 


P 


11/19/28 










46 


263 


100 


oc 


n 


11/21/28 


22.6 


35.4 


8.17 


40 




264 





r 


P 


11/21/28 


23.3 


35.3 


8.16 


36 




265 


50 


r 


P 


11/21/28 


23.2 


35.3 


8.16 


40 


48 


274 





r 


P 


11/25/28 


23.6 


36.4 


8.23 


13 


49a 


283 





r 


n 


11/28/28 


(23.3) 


(36.1) 


(8.25) 


(13)* 


50 


284 





r 


n 


11/29/28 


23.2 


36.0 


8.23 


13 




287 





oc 


P 


11/29/28 


23.2 


36.0 


8.23 


13 




288 


50 


r 


P 


11/29/28 


22.0 


36.0 


8.23 


13 


50a 


290 





r 


n 


11/30/28 


(23.0) 


(35.8) 


(8.22) 


(13)* 




292 





r 


n 


11/30/28 


(23.0) 


(35.8) 


(8.22) 


(13)* 


51 


295 


100 


r 


n 


12/ 1/28 


20.0 


35.6 


8.22 


17 




297 


50 


r 


P 


12/ 1/28 


20.5 


35.6 


8.22 


16 


53 


304 


50 


r 


n 


12/ 5/28 


21.2 


35.8 


8.20 


13 




306 





r 


P 


12/ 5/28 


22.6 


35.7 


8.22 


13 


53a 


310 





r 


n 


12/10/28 


(23.0) 


(35.6) 


(8.22) 


ill!: 




311 





r 


n 


12/10/28 


(23.0) 


35.6) 


(8.22 




313 





r 


n 


12/10/28 


(23.0) 


(35.6) (8.22) 


(li)* 


54 


320 


50 


r 


n 


12/14/28 


19.8 


35.4 


8.18 


17 




322 





r 


P 


12/14/28 


23.4 


35.5 


8.22 


9 


63a 


385 





r 


n 


1/ 1/29 
1/ 2/29 


(20.6) 


(34.6) 


(8.10) 
(8.10) 


(21)* 




388 





r 


n 


(20.6) 


(34.6 


(21)* 




393 





r 


n 


1/ 3/29 


20.6 


(34.6 


8.10 


(21 * 


64a 


401 





r 


n 


1/ 3/29 


(20.4) 


(34.6) 


(8.11 


22)* 




403 





r 


n 


1/ 4/29 


(20.4) 


(34.6) 


(8.11 


(22)* 




404 





oc 


n 


1/ 4/29 


(20.4) 


(34.6) 


(8.11) 


(22)* 


65 


408 





oc 


P 


1/ 5/29 


20.2 


34.5 


8.10 


24 


79 


481 





r 


n 


2/22/29 


25.2 


36.0 


8.17 


34 




484 





r 


P 


2/22/29 


25.2 


36.0 


8.17 


34 


82 


496 





r 


n 


2/28/29 


27.2 


36.3 


8.21 


34 




497 


50 


r 


n 


2/28/29 


27.2 


36.3 


8.21 


34 




498 





r 


P 


2/28/29 


27.2 


36.3 


8.21 


34 


86 


518 





r 


P 


3/ 9/29 


28.2 


36.2 


8.29 


20 


91 


542 





r 


P 


3/27/29 


28.7 


35.1 


8.30 


21 


93 


550 





r 


n 


3/31/29 


28.7 


34.7 


8.30 


28 




551 


50 


r 


n 


3/31/29 


28.5 


34.8 


8.30 


28 




552 





r 


P 


3/31/29 


28.7 


34.7 


8.30 


28 




553 


100 


r 


P 


3/31/29 


27.6 


35.9 


8.27 


29 


97 


574 





oc 


n 


4/28/29 


28.3 


35.2 


8.16 


24 




576 


100 


r 


n 


4/28/29 


27.6 


35.6 


8.15 


25 




577 





r 


P 


4/28/29 


28.3 


35.2 


8.16 


24 


100 


597 


100 


r 


n 


5/ 4/29 


27.6 


34.7 


8.22 


12 


101 


605 


100 


r 


n 


5/ 7/29 


25.3 


35.0 


8.23 


8 


103 


616 


50 


r 


n 


5/11/29 


25.9 


35.2 


8.25 


5 




618 





r 


P 


5/11/29 


26.0 


35.0 


8.25 


5 


105 


630 





c 


P 


5/15/29 


26.9 


34.9 


8.23 


5 


108 


648 


100 


r 


n 


5/27/29 


25.3 


35.0 


8.23 


4 


139 


854 


50 


r 


P 


9/22/29 


25.8 


34.9 


8.31 


6 


142 


878 


100 


r 


P 


10/ 7/29 


16.6 


34.5 


8.27 


7 


144 


887 





r 


P 


10/11/29 


23.3 


35.0 


8.37 


6 


145 


893 





r 


P 


10/13/29 


22.3 


34.6 


8.29 


6 




892 





r 


n 


10/13/29 


22.3 


34.6 


8.29 


6 


146 


901 


50 


r 


p 


10/15/29 


22.4 


34.9 


8.37 


6 


149 


927 





r 


P 


10/21/29 


23.5 


35.0 


8.34 


6 


150 


929 





r 


n 


10/23/29 


25.6 


34.7 


8.39 


7 




930 


50 


r 


n 


10/23/29 


25.9 


34.8 








931 


100 


r 


n 


10/23/29 


19.6 


34.7 


8.32 


' ii 


151 


938 


50 


r 


n 


10/25/29 


18.3 


34.4 








941 





r 


P 


10/25/29 


26.0 


34.0 






152 


944 





r 


n 


10/27/29 


27.5 


33.7 


8.35 


'20 




945 


50 


r 


n 


10/27/29 


14.2 


34.5 


7.87 


53 




946 


100 


r 


n 


10/27/29 


11.4 


34.7 


7.76 




157 


978 





r 


n 


11/ 6/29 


27.1 


35.3 


8.27 


*47 




979 


50 


r 


n 


11/ 6/29 


27.1 


35.2 


8.32 


60 


158 


983 





r 


n 


11/ 8/29 


28.2 


35.6 


8.34 


36 




985 


100 


r 


n 


11/ 8/29 


27.2 


35.9 


8.39 


48 


159 


992 


100 


r 


n 


11/12/29 


28.0 


35.8 


8.37 


23 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



79 



Table 19. Distributional and environmental records for Goniodoma polyedricum Pouchet 


Station 


Sample 


Depth 

(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

(°C) 


Salinity 
(o/oo) 


PH 


PO4 

mg/m3 



Atl 



1 


1 





oc 


lb 


7 


50 


r 




8 


100 


oc 


2 


14 





r 


3 


20 





r 


5a 


33 





oc 




34 





r 


6 


36 


50 


oc 




37 


100 


oc 


6b 


44 





r 




45 





oc 




46 





oc 


6c 


48 





r 


13a 


89 





r 


15 


97 





oc 




98 


50 


r 




101 


50 


r 




102 


100 


r 


16 


103 





r 




104 


50 


r 




107 


50 


r 




108 


100 


oc 


17 


110 


50 


r 




111 





r 




112 


50 


oc 




113 


100 


r 


18 


114 





oc 




115 


50 


r 




118 


50 


oc 


19 


121 


50 


r 




122 





r 




123 


50 


oc 




124 


100 


r 


20 


125 





r 




126 


50 


r 




127 


100 


r 




128 





r 




130 


100 


r 


20a 


131 





r 


21 


135 





oc 




136 


50 


r 


22 


139 





r 




144 


100 


r 


23 


145 





r 




150 


100 


r 


24 


151 





r 




155 


50 


r 


25 


157 





oc 




158 


50 


r 




161 


50 


r 


26 


163 





r 


28 


177 


50 


r 




178 


100 


r 


29 


183 


50 


r 




184 


100 


r 


30 


186 


50 


r 


31 


191 





r 


32 


194 





c 




194a 





oc 




195 


50 


r 




196 


100 


oc 


33 


197a 





oc 




199a 


100 


r 


34 


200 





oc 


35 


204 


50 


r 




205 


100 


r 




206 





oc 


35a 


208 





oc 




209 





c 


35b 


212 





c 


36 


213 





oc 




214 


50 


r 




215 


100 


r 




216 





r 



n 
n 
n 
n 
n 
n 
n 
n 
n 
n 
n 
n 
n 
n 
P 
P 
n 
n 
P 
P 
n 
n 

P 
n 
n 
n 
P 
P 
n 

P 
n 
n 
n 
P 
P 
P 
n 
n 
n 
n 
n 

P 
n 

P 
n 

P 
n 

P 
P 
n 

P 
n 
n 
n 
n 

P 
n 
n 

P 
n 
n 
P 
P 



antic 
5/12/28 
5/16/28 
5/16/28 
5/18/28 
5/21/28 
5/30/28 
5/30/28 
5/31/28 
5/31/28 
6/ 2/28 
6/ 2/28 
6/ 2/28 
6/ 3/28 
8/ 8/28 
8/11/28 
8/11/28 
8/11/28 
8/11/28 
8/13/28 
8/13/28 
8/13/28 
8/13/28 
8/15/28 
8/15/28 
8/15/28 
8/15/28 
8/17/28 
8/17/28 
8/17/28 
8/20/28 
8/20/28 
8/20/28 
8/20/28 
8/22/28 
8/22/28 
8/22/28 
8/22/28 
8/22/28 
8/23/28 
8/24/28 
8/24/28 
8/27/28 
8/27/28 
8/29/28 
8/29/28 
8/31/28 
8/31/28 
9/ 3/28 
9/13/28 
9/13/28 
9/ 5/28 
9/11/28 
9/11/28 
9/13/28 
9/13/28 
9/15/28 
10/ 3/28 
10/ 5/28 
10/ 5/28 
10/ 5/28 
10/ 5/28 
10/ 8/28 
10/ 8/28 
10/ 9/28 



Pacific 
10/26/28 
10/26/28 
10/26/28 
10/26/28 
10/27/28 
10/28/28 
10/30/28 
10/30/28 
10/30/28 
10/30/28 



24.0 


36.2 


8.16 


34 


(22.2) 
(20.3) 


(36.3) (8.25) 


38>* 
36)* 


(36.5) ( 


8.18) 


20.5 


36.4 


8.23 


58 


15.5 


36.1 


8.15 


99 


m 


(35.8) ( 
(35.8) 


8.17) 


19)* 
19)* 


8.17) 


11.6 


35.6 


8.12 


32 


11.3 


35.6 


8.08 


41 


(10.6) 


(35.4) ( 


8.12) 


;28)* 


(10.6 


(35.4) ( 


8.12) 


28* 


(10.6) 


35.4) ( 
(35.4 ( 


8.12 


28)* 


(10.6) 
(16.3) 


8.12) 


28)* 


(34.0) I 


8.13) 


15)* 


24.8 


36.4 


8.21 


11 


19.8 


36.5 


8.21 


8 


19.8 


36.5 


8.21 


8 


18.4 


36.4 


8.20 


19 


25.9 


36.2 


8.24 


8 


24.4 


36.4 


8.23 


8 


24.4 


36.4 


8.23 


8 


19.9 


36.5 


8.17 


13 


21.9 


36.6 


8.28 


12 


26.2 


36.6 


8.29 


9 


21.9 


36.6 


8.28 


12 


19.3 


35.5 


8.23 


9 


27.0 


37.0 


8.23 


5 


22.4 


36.8 


8.24 


5 


22.4 


36.8 


8.24 


5 


25.2 


37.1 


8.27 


5 


26.6 


37.0 


8.34 


5 


25.2 


37.1 


8.27 


5 


22.4 


37.0 


8.25 


5 


26.0 


36.6 


8.37 


5 


25.8 


36.6 


8.26 


3 


22.6 


36.7 


8.19 


5 


26.0 


36.6 


8.37 


5 


22.6 


36.7 


8.19 


5 


(26.6) 
(26.6) 


(36.3) 
(36.3) 


(8.32) 
(8.32) 


(4f 
(4)* 


24.4 


36.2 


8.26 


4 


26.7 


36.0 


8.26 


8 


17.5 


36.1 


7.99 


123 


27.2 


35.9 


8.25 


4 


16.6 


36.0 


8.18 


75 


27.2 


35.2 


8.32 


4 


23.1 


36.0 


8.14 


8 


27.5 


35.6 


8.31 


5 


21.5 


36.0 


8.22 


12 


21.5 


36.0 


8.22 


12 


27.6 


36.0 


8.30 


5 


26.7 


36.3 


8.26 


4 


22.8 


36.6 


8.22 


7 


27.2 


36.2 


8.29 


3 


23.1 


36.6 


8.21 


8 


27.8 


36.1 


8.29 


3 


28.5 


34.4 


8.27 


2 


28.0 


36.0 


8.23 


2 


28.0 


36.0 


8.23 


2 


27.2 


36.0 


8.24 


2 


22.2 


36.4 


8.10 


30 


28.5 


35.6 


8.23 


4 


22.3 


36.5 


8.18 


23 


28.5 


35.9 


8.28 


2 



16.8 

14.4 

27.4 

(27.0) 

(27.0) 

(27.0) 

26.5 

18.5 

14.4 

26.5 



34.7 
34.9 
29.7 
30.7 
30.7 
30.7 
31.6 
34.5 
34.9 
31.6 



7.92 
7.88 
8.31 
(8.27) 
8.27) 
8.27) 
8.23 
8.03 
7.85 
8.23 



138 

189 

15 

16 

16 

16 

16 

122 

149 

16 



80 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Table 19. Distributional and environmental records for Goniodoma polyedricum Pouchet- -Continued 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 

(°C) 



Salinity 
(o/oo) 



pH 



PC-4, 

mg/m 3 



37 


217 







218 


50 




219 


100 




220 





38 


222 







223 


50 




224 


100 


40 


229 







231 


100 




232 







233 


50 




234 


100 


41 


238 







239 


100 


41a 


240 





42 


241 







242 


50 




243 


100 


43 


248 


50 


44 


253 







254 


50 




255 


100 


45 


257 


50 




258 


100 




259 







260 


50 


46 


262 


50 




263 


100 




264 





47 


266 







267 


50 




268 


100 




269 







270 


50 


48 


271 







272 


50 




273 


100 




274 







275 


50 


49 


277 







278 


50 




279 


100 




280 







281 


50 




282 


100 


49a 


283 





50 


284 







285 


50 




286 


100 




287 







288 


50 




289 


100 


51 


290 







291 







292 







294 


50 




295 


100 




296 







297 


50 




298 


100 


52 


300 


50 




301 


100 




302 





53 


304 


50 




305 


100 




306 





53a 


307 







308 







310 







311 







312 







313 







316 





53b 


317 





54 


320 


50 




321 


100 





Pacif i 


oc 


n 


r 


n 


r 


n 


r 


P 


r 


n 


r 


n 


r 


n 


r 


n 


r 


n 


c 


P 


r 


P 


r 


P 


r 


P 


r 


P 


oc 


n 


r 


n 


r 


n 


r 


n 


r 


P 


r 


P 


r 


P 


r 


P 


r 


n 


r 


n 


oc 


P 


r 


P 


r 


n 


r 


n 


r 


P 


r 


n 


r 


n 


r 


n 


r 


P 


r 


P 


oc 


n 


oc 


n 


oc 


n 


oc 


P 


oc 


P 


oc 


n 


r 


n 


oc 


n 


oc 


P 


oc 


P 


oc 


P 


oc 


n 


oc 


n 


oc 


n 


oc 


n 


oc 


P 


r 


P 


oc 


P 


c 


n 


oc 


n 


oc 


n 


oc 


n 


oc 


n 


r 


P 


r 


P 


r 


P 


r 


n 


oc 


n 


oc 


P 


c 


n 


oc 


n 


oc 


P 


r 


n 


oc 


n 


oc 


n 


oc 


n 


oc 


n 


oc 


n 


r 


n 


oc 


n 


oc 


n 


oc 


n 



c --Continued 
11/ 1/28 
11/ 1/28 
11/ 1/28 
11/ 1/28 
11/ 3/28 
11/ 3/28 
11/ 3/28 
11/ 8/28 
11/ 8/28 
11/ 8/28 
11/ 8/28 
11/ 8/28 
11/10/28 
11/10/28 
11/12/28 
11/13/28 
11/13/28 
11/13/28 
11/15/28 
11/17/28 
11/17/28 
11/17/28 
11/19/28 
11/19/28 
11/19/28 
11/19/28 
11/21/28 
11/21/28 
11/21/28 
11/23/28 
11/23/28 
11/23/28 
11/23/28 
11/23/28 
11/25/28 
11/25/28 
11/25/28 
11/25/28 
11/25/28 
11/27/28 
11/27/28 
11/27/28 
11/27/28 
11/27/28 
11/27/28 
11/28/28 
11/29/28 
11/29/28 
11/29/28 
11/29/28 
11/29/28 
11/29/28 
12/ 1/28 
12/ 1/28 
12/ 1/28 
12/ 1/28 
12/ 1/28 
12/ 1/28 
12/ 1/28 
12/ 1/28 
12/ 3/28 
12/ 3/28 
12/ 3/28 
12/ 5/28 
12/ 5/28 
12/ 5/28 
12/ 6/28 
12/ 6/28 
12/10/28 
12/10/28 
12/10/28 
12/10/28 
12/12/28 
12/12/28 
12/14/28 
12/14/28 



27.1 
18.8 
15.1 
27.1 
26.5 
21.3 
15.6 



22. 
13. 
22. 
15. 
13. 
20. 
14. 
(19.6) 
18.7 
17.2 
13.8 
17.0 
20.7 
20.4 
13.8 
22.4 
18.6 
22.4 
22.4 
23.2 
22.5 
23.3 
23.9 
23.8 
22.7 
23.9 
23.8 
23.6 
23.6 
22.7 
23.6 
23.6 
23.4 
22.6 
21.6 
23.4 
22.6 
21.6 
(23.2) 
(23.2) 
22.0 
20.5 
23.2 
22.0 
20.5 
22.8 
22.8 
22.8 
20.5 
20.0 
22.8 
20.5 
20.0 
20.2 
18.2 
22.5 
21.2 
19.9 
22.6 
(23.0) 
(23.0 
23.0) 
(23.0) 
(23.0) 
(23.0) 
(23.0) 
(23.0) 
19.8 
18.7 



31.7 


8.28 


15 


34.5 


8.00 


121 


34.9 


7.82 


153 


31.7 


8.28 


15 


32.9 


8.33 


20 


34.4 


8.14 


35 


34.9 


7.91 


166 


33.7 


8.21 


24 


35.0 


7.85 


159 


33.7 


8.21 


24 


34.9 


7.87 


161 


35.0 


7.85 


159 


34.2 


8.11 


32 


35.0 


7.91 


152 


(34.5) 


(8.09) 


(39)* 


34.7 


8.06 


45 


34.9 


7.99 


68 


35.0 


7.91 


150 


34.9 


7.93 


80 


34.9 


8.03 


38 


34.9 


8.04 


34 


35.0 


7.85 


70 


35.2 


8.13 


46 


35.1 


8.00 


50 


35.3 


8.12 


38 


35.2 


8.13 


46 


35.3 


8.16 


40 


35.4 


8.17 


40 


35.3 


8.16 


36 


36.0 


8.23 


17 


36.0 


8.23 


20 


36.2 


8.23 


20 


36.0 


8.23 


17 


36.0 


8.23 


20 


36.4 


8.23 


13 


36.4 


8.24 


16 


36.3 


8.26 


16 


36.4 


8.23 


13 


36.4 


8.24 


16 


36.2 


8.27 


13 


36.1 


8.26 


13 


35.9 


8.26 


13 


36.2 


8.27 


13 


36.1 


8.26 


13 


35.9 


8.26 


13 


(36.0) 
(36.0) 


(8.23) 
(8.23) 


(13)* 


(13)* 


35.9 


8.23 


13 


35.7 


8.22 


13 


36.0 


8.23 


13 


35.9 


8.23 


13 


35.7 


8.22 


13 


35.6 


8.22 


16 


35.6 


8.22 


16 


35.6 


8.22 


16 


35.6 


8.22 


17 


35.6 


8.22 


17 


35.6 


8.22 


16 


35.6 


8.22 


17 


35.6 


8.22 


17 


35.6 


8.20 


8 


35.2 


8.17 


8 


35.4 


8.21 


8 


35.8 


8.20 


13 


35.6 


8.19 


13 


35.7 


8.22 


13 


(35.6) 


(8.22, 


(11)* 


(35.6 


8.22 


(U * 


(35.6 


(8.22 


(11)* 


(35.6 


(8.22 


(11)* 


(35.6 


(8.22 


(11 * 


(35.6 


(8.22 


(11 * 


(35.6 


(8.22 


(11)* 


(35.6 ( 


(8.22; 


(11)* 


35.4 


8.18. 


17 


35.4 


8.16 


20 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



81 



Table 19. Distributional and environmental records for Goniodoma polyedricum Pouchet--Continued 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 

(°C) 



Salinity 
(o/oo) 



PH 



PO4 
mg/m^ 











Pacific 


--Continued 










54 


322 





oc 


p 


12/14/28 


23.4 


35.5 


8.22 


9 


55 


324 


50 


oc 


n 


12/16/28 


18.7 


35.0 


8.18 


12 




325 


100 


r 


n 


12/16/28 


16.7 


34.9 


7.17 


12 


56 


328 





oc 


n 


12/18/28 


20.8 


34.9 


8.13 


9 




329 


50 


r 


n 


12/18/28 


18.5 


35.1 


8.14 


9 




330 


100 


r 


n 


12/18/28 


16.6 


34.8 


8.11 


12 




331 





r 


P 


12/18/28 


20.8 


34.9 


8.13 


9 




332 


50 


oc 


P 


12/18/28 


18.5 


35.1 


8.14 


9 




333 


100 


r 


P 


12/18/28 


16.6 


34.8 


8.11 


12 


57 


334 





oc 


n 


12/20/28 


19.0 


34.5 


8.14 


20 




335 





r 


n 


12/20/28 


19.0 


34.5 


8.14 


20 




336 


50 


r 


n 


12/20/28 


15.6 


34.3 


8.14 


21 




338 





r 


P 


12/20/28 


19.0 


34.5 


8.14 


20 


60 


361 





r 


n 


12/26/28 


15.0 


34.0 


8.07 


50 


61a 


369 





r 


n 


12/28/28 


(18.1) 


(34.1) 


(8.09) 


(39)* 


62 


373 


100 


r 


n 


12/30/28 


13.1 


34.2 


8.06 


48 




374 





r 


P 


12/30/28 


19.2 


34.2 


8.12 


32 




376 


100 


r 


P 


12/30/28 


13.1 


34.2 


8.06 


48 


63 


377 





r 


n 


12/31/28 


20.5 


34.6 


8.07 


21 




378 





r 


n 


12/31/28 


20.5 


34.6 


8.07 


21 




379 





r 


n 


1/ 1/29 


20.5 


34.6 


8.07 


21 




380 


50 


r 


n 


1/ 1/29 


17.0 


34.6 


8.08 


25 




381 


100 


r 


n 


1/ 1/29 


15.6 


34.6 


8.08 


24 




382 





r 


P 


1/ 1/29 


20.5 


34.6 


8.07 


21 




385 





r 


n 


1/ 1/29 


20.5 


34.6 


8.07 


21 




386 





oc 


n 


1/ 1/29 


20.5 


34.6 


8.07 


21 




389 





r 


n 


1/ 2/29 


20.5 


34.6 


8.07 


21 




391 





r 


n 


1/ 3/29 


20.5 


34.6 


8.07 


21 




392 





r 


n 


1/ 3/29 


20.5 


34.6 


8.07 


21 




393 





r 


n 


1/ 3/29 


20.5 


34.6 


8.07 


21 


64 


394 





r 


n 


1/ 3/29 


20.6 


34.6 


8.12 


21 




398 





r 


P 


1/ 3/29 


20.6 


34.6 


8.12 


21 




400 


100 


r 


P 


1/ 3/29 


15.8 


34.5 


8.10 


32 




402 





r 


n 


1/ 4/29 


20.6 


34.6 


8.12 


21 




403 





r 


n 


1/ 4/29 


20.6 


34.6 


8.12 


21 




404 





r 


n 


1/ 4/29 


20.6 


34.6 


8.12 


21 


65 


405 





r 


n 


1/ 5/29 


20.2 


34.5 


8.10 


24 




406 


50 


r 


n 


1/ 5/29 


16.5 


34.5 


8.10 


25 




408 





r 


P 


1/ 5/29 


20.2 


34.5 


8.10 


24 




409 


50 


r 


P 


1/ 5/29 


16.5 


34.5 


8.10 


25 


66 


412 


100 


r 


n 


1/ 7/29 


17.8 


34.9 


8.12 


21 




413 





r 


P 


1/ 7/29 


19.4 


34.7 


8.10 


29 




415 


100 


r 


P 


1/ 7/29 


17.8 


34.9 


8.12 


21 


67 


416 





oc 


n 


1/ 8/29 


19.3 


34.9 


8.11 


21 




417 


50 


r 


n 


1/ 8/29 


17.4 


34.7 


8.11 


20 




418 


100 


oc 


n 


1/ 8/29 


16.2 


34.6 


8.05 


40 


68 


422 





r 


P 


1/10/29 


19.2 


35.1 


8.14 


29 




423 


50 


r 


P 


1/10/29 


18.2 


35.0 


8.14 


29 


69 


424 





oc 


n 


1/12/29 


21.1 


35.2 


8.12 


62 




425 


50 


oc 


n 


1/12/29 


17.4 


35.1 


7.99 


151 




426 


100 


oc 


n 


1/12/29 


14.6 


34.8 


7.86 


198 




427 





oc 


P 


1/12/29 


12.1 


35.2 


8.12 


62 




428 


50 


oc 


P 


1/12/29 


17.4 


35.1 


7.99 


151 




429 


100 


r 


P 


1/12/29 


14.6 


34.8 


7.86 


198 


70 


434 





oc 


P 


1/13/29 


21.2 


35.1 


8.05 


103 


71 


438 





oc 


n 


2/ 6/29 


23.5 


35.2 


8.13 


58 




439 


50 


r 


n 


2/ 6/29 


16.7 


35.1 


7.90 


150 




440 


100 


r 


n 


2/ 6/29 


13.9 


35.0 


7.71 


220 




441 





oc 


P 


2/ 6/29 


23.5 


35.2 


8.13 


58 


72 


446 





r 


P 


2/ 8/29 


24.9 


35.3 


8.16 


50 




447 


50 


oc 


P 


2/ 8/29 


18.7 


35.4 


8.12 


60 


73 


449 





oc 


n 


2/10/29 


25.3 


35.4 


8.21 


44 




451 


50 


r 


n 


2/10/29 


18.7 


35.4 


8.05 


122 




452 


100 


oc 


n 


2/10/29 


14.7 


35.0 


7.80 


178 




453 





r 


P 


2/10/29 


25.3 


35.4 


8.21 


44 




455 


100 


r 


P 


2/10/29 


14.7 


35.0 


7.80 


178 


74 


459 





r 


P 


2/12/29 


24.2 


35.6 


8.17 


68 


75 


462 





oc 


n 


2/14/29 


22.8 


35.8 


8.18 


44 




465 





r 


P 


2/14/29 


22.8 


35.8 


8.18 


44 


76 


467 





oc 


n 


2/16/29 


23.4 


35.9 


8.15 


50 




470 





r 


P 


2/16/29 


23.4 


35.9 


8.15 


50 


77 


473 





r 


P 


2/18/29 


23.7 


36.0 


8.19 


16 




474 


50 


oc 


P 


2/18/29 


23.5 


36.0 


8.19 


16 


78 


475 





r 


n 


2/20/29 


24.6 


36.0 


8.17 


32 




477 


100 


oc 


n 


2/20/29 


21.9 


36.2 


8.14 


34 


79 


481 





r 


n 


2/22/29 


25.2 


36.0 


8.17 


34 



82 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Table 19. Distributional and environmental records for Goniodoma polyedricum Pouchet- -Continued 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 
(°C) 


Salinity 
(o/oo) 


PH 


P °/ 4 3 

mg/m* 5 










Pacific 


--Continued 








79 


483 


100 


oc 


n 


2/22/29 


21.8 


36.2 


8.13 


45 




484 





r 


P 


2/22/29 


25.2 


36.0 


8.17 


34 




485 


50 


r 


P 


2/22/29 


24.5 


36.1 


8.17 


34 


80 


486 





r 


n 


2/24/29 


26.0 


35.9 


8.20 


36 




487 


50 


r 


n 


2/24/29 


25.9 


36.0 


8.19 


29 




488 





oc 


P 


2/24/29 


26.0 


35.9 


8.20 


36 




489 


50 


r 


P 


2/24/29 


25.9 


36.0 


8.19 


29 


81 


491 





oc 


n 


2/26/29 


26.5 


35.8 


8.19 


38 




492 


50 


r 


n 


2/26/29 


26.4 


35.9 


8.19 


38 




493 





r 


P 


2/26/29 


26.5 


35.8 


8.19 


38 




494 


50 


r 


P 


2/26/29 


26.4 


35.9 


8.19 


38 


82 


497 


50 


r 


n 


2/28/29 


27.2 


36.3 


8.21 


34 




498 





r 


P 


2/28/29 


27.2 


36.3 


8.21 


34 


83 


501 





oc 


n 


3/ 2/29 


27.5 


36.3 


8.24 


29 




502 


50 


oc 


n 


3/ 2/29 


27.4 


36.5 


8.24 


25 




503 





r 


P 


3/ 2/29 


27.5 


36.3 


8.24 


29 


84 


505 





r 


n 


3/ 4/29 


27.8 


36.2 


8.23 


24 




506 


50 


r 


n 


3/ 4/29 


27.5 


36.4 


8.21 


24 




507 





r 


P 


3/ 4/29 


27.8 


36.2 


8.23 


24 


85 


510 





r 


n 


3/ 6/29 


27.9 


36.2 


8.22 


40 




511 


50 


r 


n 


3/ 6/29 


27.8 


36.2 


8.22 


40 




512 





r 


P 


3/ 6/29 


27.9 


36.2 


8.22 


40 




513 


50 


r 


P 


3/ 6/29 


27.8 


36.2 


8.22 


40 


86 


515 





oc 


n 


3/ 9/29 


28.3 


36.2 


8.29 


20 




516 





oc 


n 


3/ 9/29 


28.3 


36.2 


8.29 


20 




518 





oc 


P 


3/ 9/29 


28.3 


36.2 


8.29 


20 




519 


50 


r 


P 


3/ 9/29 


27.4 


36.2 


8.29 


17 


87 


521 





r 


n 


3/11/29 


27.8 


36.1 


8.28 


17 




522 


50 


r 


n 


3/11/29 


26.5 


36.1 


8.26 


20 




523 





r 


P 


3/11/29 


27.8 


36.1 


8.28 


17 




524 


50 


oc 


p 


3/11/29 


26.5 


36.1 


8.26 


20 


88 


526 





oc 


n 


3/21/29 


28.5 


35.9 


8.23 


16 




527 


50 


r 


n 


3/21/29 


28.4 


35.9 


8.25 


13 


89 


528 





r 


n 


3/23/29 


28.4 


35.6 


8.25 


21 




529 


50 


r 


n 


3/23/29 


28.6 


35.8 


8.27 


12 




530 





oc 


p 


3/23/29 


28.4 


35.6 


8.25 


21 




531 


100 


r 


p 


3/23/29 


26.4 


36.0 


8.24 


12 




532 





r 


n 


3/23/29 


28.4 


35.6 


8.25 


21 


90 


533 





oc 


n 


3/25/29 


28.5 


35.5 


8.27 


21 




534 


50 


oc 


n 


3/25/29 


28.6 


35.6 


8.26 


21 




535 





oc 


p 


3/25/29 


28.5 


35.5 


8.27 


21 




536 


50 


r 


p 


3/25/29 


28.6 


35.6 


8.26 


21 


91 


540 





oc 


n 


3/27/29 


28.7 


35.1 


8.30 


21 




541 


50 


oc 


n 


3/27/29 


28.5 


35.2 


8.30 


24 




542 





r 


p 


3/27/29 


28.7 


35.1 


8.30 


21 




543 


50 


r 


p 


3/27/29 


28.5 


35.2 


8.30 


24 




544 


100 


r 


p 


3/27/29 


25.8 


36.0 


8.25 


30 


92 


545 





oc 


n 


3/29/29 


28.5 


35.3 


8.29 


28 


93 


550 





c 


n 


3/31/29 


28.7 


34.7 


8.30 


28 




551 


50 


oc 


n 


3/31/29 


28.5 


34.8 


8.30 


28 




552 





oc 


p 


3/31/29 


28.7 


34.7 


8.30 


28 


94 


557 





r 


n 


4/22/29 


29.5 


34.7 


8.25 


14 




559 


100 


r 


n 


4/22/29 


28.5 


35.6 


8.21 


25 




562 


100 


r 


p 


4/22/29 


28.5 


35.6 


8.21 


25 


95 


563 


50 


oc 


n 


4/24/29 


29.3 


34.9 


8.24 


16 




564 


100 


oc 


n 


4/24/29 


28.5 


35.4 


8.22 


21 




565 





r 


p 


4/24/29 


29.4 


34.7 


8.26 


14 




566 


50 


r 


p 


4/24/29 


29.3 


34.9 


8.24 


16 




567 


100 


r 


p 


4/24/29 


28.5 


35.4 


8.22 


21 




568a 





r 


n 


4/24/29 


29.4 


34.7 


8.26 


14 


96 


568 





oc 


n 


4/26/29 


29.3 


35.3 


8.23 


12 




569 


50 


oc 


n 


4/26/29 


29.2 


35.3 


8.23 


12 




570 


100 


oc 


n 


4/26/29 


28.2 


35.7 


8.19 


25 


97 


574 





c 


n 


4/28/29 


28.3 


35.2 


8.16 


24 




575 


50 


oc 


n 


4/28/29 


28.0 


35.4 


8.16 


21 




577 





r 


p 


4/28/29 


28.3 


35.2 


8.16 


24 


98 


584 





oc 


p 


4/30/29 


27.0 


35.3 


8.16 


24 




588 


100 


oc 


P 


4/30/29 


26.7 


35.4 


8.14 


32 


99 


589 





oc 


n 


5/ 2/29 


27.9 


34.9 


8.21 


12 




590 


50 


oc 


n 


5/ 2/29 


27.8 


34.9 


8.22 


12 




591 


100 


oc 


n 


5/ 2/29 


27.8 


35.0 


8.22 


17 




592 





oc 


P 


5/ 2/29 


27.9 


34.9 


8.21 


12 




594 


100 


r 


P 


5/ 2/29 


27.8 


35.0 


8.22 


17 




595 





r 


n 


5/ 2/29 


27.9 


34.9 


8.21 


12 


100 


596 


50 


oc 


n 


5/ 4/29 


27.6 


34.7 


8.21 


10 




597 


100 


oc 


n 


5/ 4/29 


27.6 


34.7 


8.22 


12 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



83 



Table 19. Distributional and environmental records for Goniodoma polyedricum Pouchet- -Continued 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

(°C) 


Salinity 
(o/oo) 


PH 


PO4 

mg/m3 










Pacific 


--Continued 








100 


598 





c 


P 


5/ 4/29 


27.7 


34.7 


8.21 


10 




599 


50 


oc 


P 


5/ 4/29 


27.6 


34.7 


8.21 


10 




602 


100 


oc 


P 


5/ 4/29 


27.6 


34.7 


8.22 


12 


101 


603 





c 


n 


5/ 7/29 


26.3 


34.7 


8.24 


8 




604 


50 


c 


n 


5/ 7/29 


26.2 


34.7 


8.24 


8 




606 





r 


P 


5/ 7/29 


26.3 


34.7 


8.24 


8 


102 


609 





oc 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




610 


50 


oc 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




611 


100 


oc 


n 


5/ 9/29 


25.6 


35.0 


8.23 


8 




612 





oc 


P 


5/ 9/29 


25.8 


35.0 


8.24 


8 




613 


50 


r 


P 


5/ 9/29 


25.8 


35.0 


8.24 


8 


103 


615 





oc 


n 


5/11/29 


26.0 


35.0 


8.25 


5 




616 


50 


oc 


n 


5/11/29 


25.8 


35.2 


8.25 


5 




617 


100 


oc 


n 


5/11/29 


24.8 


35.2 


8.25 


5 




618 





r 


P 


5/11/29 


26.0 


35.0 


8.25 


5 




619 


50 


r 


P 


5/11/29 


25.8 


35.2 


8.25 


5 


104 


621 





oc 


n 


5/13/29 


26.1 


35.2 


8.24 


7 




622 


50 


oc 


n 


5/13/29 


25.8 


35.2 


8.24 


7 




624 





oc 


P 


5/13/29 


26.1 


35.2 


8.24 


7 




625 


50 


oc 


P 


5/13/29 


25.8 


35.2 


8.24 


7 


105 


627 


50 


c 


n 


5/15/29 


26.8 


34.9 


8.23 


5 




628 


50 


r 


n 


5/15/29 


26.8 


34.9 


8.23 


5 




629 


100 


oc 


n 


5/15/29 


25.2 


35.1 


8.23 


5 




630 





oc 


P 


5/15/29 


26.9 


34.9 


8.23 


5 




631 


50 


oc 


P 


5/15/29 


26.8 


34.9 


8.23 


5 


106 


633 





oc 


n 


5/17/29 


27.2 


35.0 


8.23 


5 




635 


100 


oc 


n 


5/17/29 


25.6 


35.1 


8.23 


5 




637 


50 


r 


P 


5/17/29 


27.0 


35.0 


8.23 


5 




638 


100 


r 


P 


5/17/29 


25.6 


35.1 


8.23 


5 


107 


640 


50 


oc 


n 


5/19/29 


27.9 


34.4 


8.23 


4 




641 


100 


oc 


n 


5/19/29 


26.8 


34.9 


8.23 


11 




642 





r 


P 


5/19/29 


28.0 


34.4 


8.23 


5 




644 


100 


oc 


P 


5/19/29 


26.8 


34.9 


8.23 


11 




645 


50 


r 


P 


5/19/29 


27.9 


34.4 


8.23 


4 


108 


646 





r 


n 


5/27/29 


28.4 


35.0 


8.25 


4 




647 


50 


oc 


n 


5/27/29 


26.8 


35.0 


8.25 


4 




648 


100 


oc 


n 


5/27/29 


25.2 


35.0 


8.23 


4 




650 


50 


r 


P 


5/27/29 


26.8 


35.0 


8.24 


4 


Guam 


652 





oc 


n 


5/-/29 










109 


654 





oc 


n 


5/29/29 


27.4 


35.6 


8.23 


3 




657 




r 




5/29/29 


27.4 


35.0 


8.23 


3 




658 


50 


oc 


P 


5/29/29 


23.1 


35.0 


8.22 


3 




659 


100 


oc 


P 


5/29/29 


19.4 


34.8 


8.18 


5 




660 





r 


P 


5/29/29 


27.4 


35.0 


8.23 


3 


110 


661 





r 


n 


5/31/29 


23.9 


34.7 


8.18 


5 




662 


50 


r 


n 


5/31/29 


18.4 


34.8 


8.16 


7 




663 


100 


oc 


n 


5/31/29 


17.9 


34.7 


8.14 


11 




664 





oc 


P 


5/31/29 


23.9 


34.7 


8.18 


5 




665 


50 


r 


P 


5/31/29 


18.4 


34.8 


8.16 


7 




666 
667 
668 


100 


r 


P 


5/31/29 


17.9 


34.7 


8.14 


11 


111 


' 


oc 


n 


6/ 3/29 


20.1 


34.5 


8.18 


5 




669 


50 


r 


n 


6/ 3/29 


19.4 


34.6 


8.17 


5 




671 





oc 


P 


6/ 3/29 


20.1 


34.5 


8.18 


5 




672 


50 


r 


P 


6/ 3/29 


19.4 


34.6 


8.17 


5 


112 


674 





r 


n 


6/ 5/29 


23.2 


34.6 


8.22 


7 




675 


50 


oc 


n 


G/ 5/29 


21.7 


34.6 


8.23 


7 




676 


100 


oc 


n 


6/ 5/29 


19.8 


34.7 


8.20 


8 




677 





oc 


P 


6/ 5/29 


23.2 


34.6 


8.22 


7 




678 


50 


r 


P 


6/ 5/29 


21.7 


34.6 


8.23 


7 




679 


100 


r 


P 


6/ 5/29 


19.8 


34.7 


8.20 


8 


113 


681 


50 


oc 


n 


6/25/29 


23.8 


34.6 


8.25 


5 




682 


100 


oc 


n 


6/25/29 


■ai.6 


34.7 


8.23 


8 




683 





oc 


P 


6/25/29 


24.2 


34.5 


8.25 


5 




685 


100 


r 


P 


6/25/29 


21.5 


34.7 


8.23 


8 


115 


695 





r 


P 


6/29/29 


20.6 


34.6 


8.19 


4 


117 


710 


100 


r 


n 


7/ 3/29 


8.8 


34.1 


7.98 


84 


130 


792 





r 


P 


9/ 4/29 


16.2 


33.4 


8.34 


36 


131 


794 





r 


P 


9/ 6/29 


19.3 


33.4 


8.34 




132 


797 





oc 


n 


9/ 8/29 


21.0 


33.9 


8.34 


15* 




801 





r 


P 


9/ 8/29 


21.0 


33.9 


8.34 


15 




798 


50 


r 


n 


9/ 8/29 


17.6 


33.9 


8.33 


19 




802 


50 


r 


P 


9/ 8/29 


17.6 


33.9 


8.33 


19 




803 


100 


r 


P 


9/ 8/29 


14.3 


33.4 


8.30 


16 


133 


804 





r 


n 


9/10/29 


22.7 


34.7 


8.47 


7 




806 


100 


r 


n 


9/10/29 


18.4 


34.8 


8.31 


7 



84 STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 
Table 19. Distributional and environmental records for Goniodoma polyedricum Pouchet--Continued 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

rc) 


Salinity 
(o/oo) 


PH 


p 04„ 

mg/m 3 










Pacific- 


--Continued 








133 


814 


100 


r 


P 


9/10/29 


18.4 


34.8 


8.31 


7 


134 


809 


50 


r 


n 


9/12/29 


19.8 


34.6 


8.34 


6 




817 


100 


r 


P 


9/12/29 


18.1 


34.6 


8.34 


6 


135 


820 





r 


n 


9/14/29 


23.8 


35.1 


8.37 


7 




821 


50 


r 


n 


9/14/29 


21.5 


35.0 


8.37 


5 




825 


50 


r 


P 


9/14/29 


21.5 


35.0 


8.37 


5 




826 


100 


r 


P 


9/14/29 


18.7 


34.8 


8.34 


5 


136 


827 





r 


n 


9/16/29 


24.6 


35.4 


8.37 


3 




829 


100 


oc 


n 


9/16/29 


18.6 


35.0 


8.39 


3 




833 


50 


r 


P 


9/16/29 


21.4 


35.1 


8.39 


3 




834 


100 


r 


p 


9/16/29 


18.6 


35.0 


8.39 


3 


137 


837 


50 


r 


P 


9/18/29 


24.4 


35.1 


8.34 


4 


138 


843 





oc 


n 


9/26/29 


26.1 


34.8 


8.35 


5 




847 





r 


P 


9/26/29 


26.1 


34.8 


8.35 


5 




844 


50 


r 


n 


9/26/29 


25.6 


34.7 


8.30 


3 




845 


100 


oc 


n 


9/26/29 


22.2 


34.8 


8.31 


3 


139 


853 





r 


P 


9/22/29 


26.7 


34.8 


8.34 


6 




850 


50 


oc 


n 


9/22/29 


25.8 


34.9 


8.31 


6 




854 


50 


r 


P 


9/22/29 


25.8 


34.9 


8.31 


6 


140 


860 





r 


P 


10/ 3/29 


26.9 


35.0 


8.42 


7 




957 


50 


oc 


n 


10/ 3/29 


26.9 


35.0 


8.39 


7 




861 


50 


r 


P 


10/ 3/29 


26.9 


35.0 


8.39 


7 




858 


100 


oc 


n 


10/ 3/29 


25.5 


35.0 


8.34 


7 




863 


100 


r 


P 


10/ 3/29 


25.5 


35.0 


8.34 


7 


141 


864 





r 


n 


10/ 5/29 


25.9 


35.2 


8.34 


5 




868 





r 


P 


10/ 5/29 


25.9 


35.2 


8.34 


5 




865 


50 


oc 


n 


10/ 5/29 


24.8 


35.3 


8.34 


5 




869 


50 


r 


P 


10/ 5/29 


24.8 


35.3 


8.34 


5 




871 


100 


r 


P 


10/ 5/29 


20.0 


35.0 


8.33 


5 


142 


872 





oc 


n 


10/ 7/29 


24.1 


34.8 


8.33 


5 




874 


100 


oc 


n 


10/ 7/29 


16.6 


34.4 


8.27 


7 




876 





oc 


p 


10/ 7/29 


24.1 


34.8 


8.33 


5 




877 


50 


oc 


P 


10/ 7/29 


21.8 


34.8 


8.30 


5 




878 


100 


oc 


P 


10/ 7/29 


16.6 


34.4 


8.27 


7 




879 


100 


oc 


P 


10/ 7/29 


16.6 


34.4 


8.27 


7 


143 


881 





oc 


n 


10/ 9/29 


22.4 


34.4 


8.30 


6 




884 





r 


p 


10/ 9/29 


22.4 


34.4 


8.30 


6 




882 


50 


oc 


n 


10/ 9/29 


19.0 


34.2 


8.34 


6 




885 


50 


r 


p 


10/ 9/29 


19.0 


34.2 


8.34 


6 




883 


100 


r 


n 


10/ 9/29 


13.8 


34.1 


8.30 


10 


144 


886 





r 


n 


10/11/29 


23.3 


35.0 


8.37 


6 




889 


100 


r 


p 


10/11/29 


16.6 


34.5 


8.37 


6 


145 


890 





c 


n 


10/13/29 


22.3 


34.6 


8.29 


6 




893 





r 


P 


10/13/29 


22.3 


34.6 


8.29 


6 




891 


50 


oc 


n 


10/13/29 


18.7 


34.3 


8.34 


6 




894 


50 


r 


P 


10/13/29 


18.7 


34.3 


8.34 


6 




892 


100 


r 


n 


10/13/29 


16.0 


34.1 


8.31 


6 




895 


100 


r 


P 


10/13/29 


16.0 


34.1 


8.31 


6 


146 


896 





r 


n 


10/15/29 


22.4 


34.9 


8.37 


6 




897 


50 


r 


n 


10/15/29 


22.4 


34.9 


8.30 


6 


147 


903 





r 


n 


10/17/29 


23.3 


35.3 


8.26 


8 




907 





r 


P 


10/17/29 


23.3 


35.3 


8.26 


8 




904 


50 


r 


n 


10/17/29 


23.1 


35.3 


8.29 


5 




909 


100 


r 


p 


10/17/29 


19.2 


35.0 


8.29 


5 


148 


910 





r 


n 


10/19/29 


23.4 


35.2 








917 





r 


P 


10/19/29 


23.4 


35.2 


. . . 






912 


100 


r 


n 


10/19/29 


20.0 


35.0 




. . 


149 


920 





r 


n 


10/21/29 


23.5 


35.0 


8.34 


6 




927 





r 


p 


10/21/29 


23.5 


35.0 


8.34 


6 




928 


50 


r 


p 


10/21/29 


23.3 


35.0 


8.37 


6 


150 


929 





oc 


n 


10/23/29 


25.6 


34.7 


8.39 


7 




930 


50 


oc 


n 


10/23/29 


22.8 


34.8 


8.35 


10 




934 


50 


r 


p 


10/23/29 


22.8 


34.8 


8.35 


10 




931 


100 


oc 


n 


10/23/29 


19.6 


34.6 


8.32 


11 




936 


100 


r 


p 


10/23/29 


19.6 


34.6 


8.32 


11 


151 


937 





r 


n 


10/26/29 


26.0 


34.0 








941 





r 


p 


10/26/29 


26.0 


34.0 








938 


50 


r 


n 


10/26/29 


18.3 


34.4 








942 


50 


r 


P 


10/26/29 


18.3 


34.4 








939 


100 


r 


n 


10/26/29 


12.5 


34.6 


. . . 




152 


944 





r 


n 


10/27/29 


27.4 


33.7 


8.35 


*20 




948 





r 


P 


10/27/29 


27.4 


33.7 


8.35 


20 




945 


50 


oc 


n 


10/27/29 


14.2 


34.5 


7.87 


53 




946 


100 


r 


n 


10/27/29 


11.4 


34.7 


7.76 


75 


153 


951 





oc 


n 


10/29/29 


28.1 


34.2 


8.47 


7 




955 





r 


P 


10/29/29 


28.1 


34.2 


8.47 


7 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



85 



Table 19. Distributional and environmental records for Goniodoma polyedricum Pouchet--Concluded 



1 

Apparatus Date 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Temperature Salinity 
(°C) (o/oo) 



PH 



P °/ 4 3 
mg/m° 



153 


952 


50 




956 


50 




953 


100 




957 


100 


154 


959 


50 


155 


965 







966 


50 




967 


100 


156 


972 







974 


100 


157 


978 







979 


50 




980 


100 


158 


983 







984 


50 




985 


100 


159 


990 







991 


50 




992 


100 


160 


1000 






oc 

r 

r 

r 

r 

oc 

r 

oc 

oc 

oc 

r 

r 

r 

oc 

oc 

r 

r 

r 

r 

r 



Pacific 
n 

P 
n 

P 
n 

n 

P 
n 
n 
n 
n 
n 
n 
n 
n 
n 
n 
n 
n 
n 



Con 

0/29/29 
0/29/29 
0/29/29 
0/29/29 
0/31/29 
1/ 2/29 
1/ 2/29 
1/ 2/29 
1/ 4/29 
1/ 4/29 
1/ 6/29 
1/ 6/29 
1/ 6/29 
1/ 8/29 
1/ 8/29 
1/ 8/29 
1/11/29 
1/11/29 
1/11/29 
1/13/29 



28.1 
28.1 
20.5 
20.5 
28.2 
27.8 
27.7 
27.2 
27.6 
26.4 
27.1 
27.1 
26.8 
28.2 
28.2 
27.6 
28.6 
28.5 
28.0 
28.6 



34.4 


8.39 


7 


34.4 


8.39 


7 


34.7 


8.28 


31 


34.7 


8.28 


31 


34.2 


8.40 


7 


34.9 


8.29 


29 


34.9 


8.30 


30 


35.0 


8.30 


35 


35.0 


8.34 


28 


35.1 


8.30 


48 


35.3 


8.27 


47 


35.2 


8.32 


60 


35.5 


8.30 


64 


35.6 


8.34 


36 


35.6 


8.39 


50 


35.9 


8.39 


43 


35.7 


8.37 


15 


35.7 


8.39 


15 


35.7 


8.37 


23 


35.3 


8.37 


12 



Table 20. Distributional and environmental records for Gonyaulax pacifica Kofoid 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Apparatus Date 



Temperature Salinity 

(°C) (o/oo) 



pH 



P04 

mg/m3 



15 


98 


50 




99 


100 




101 


50 




102 


100 


16 


104 


50 




108 


100 


17 


110 


50 




111 





18 


114 







118 


50 




115 


50 




119 


100 


19 


121 


50 




123 


50 


20 


126 


50 




129 


50 




130 


100 


21 


136 


50 




137 


100 


22 


143 


50 


23 


149 


50 


25 


158 


50 




161 


50 




162 


100 


26 


164 


50 




165 


100 


27 


167 







171 


50 


28 


178 


100 


29 


180 


50 


30 


189 


50 


36 


215 


100 


45 


257 


50 




258 


100 




259 





46 


261 







262 


50 




263 


100 




264 







265 


50 


47 


266 







267 


50 




268 


100 




270 


50 


49 


279 


100 



oc 

oc 

r 

oc 

r 

r 

r 

r 

r 

r 

r 

oc 

r 

r 

r 

r 

r 

r 

r 

r 

r 

r 

oc 

r 

r 

r 

r 

r 

r 

r 

r 



r 

r 

r 

r 

r 

r 

oc 

r 

r 

r 

r 

oc 

oc 

oc 



/ 


Atlantic 




p 


8/11/28 


19.8 


p 


8/11/28 


18.4 


n 


8/11/28 


19.8 


n 


8/11/28 


18.4 


P 


8/13/28 


24.4 


n 


8/13/28 


19.9 


P 


8/15/28 


21.9 


D 


8/15/28 


26.2 


P 


8/17/28 


27.0 


n 


8/17/28 


22.4 


P 


8/17/28 


22.4 


n 


8/17/28 


20.4 


P 


8/20/28 


25.2 


n 


8/20/28 


25.2 


P 


8/22/28 


25.8 


n 


8/22/28 


25.8 


n 


8/22/28 


22.6 


n 


8/24/28 


24.4 


n 


8/24/28 


21.0 


n 


8/27/28 


24.5 


n 


8/29/28 


20.9 


P 


9/ 3/28 


21.5 


n 


9/ 3/28 


21.5 


n 


9/ 3/28 


14.6 


P 


9/ 5/28 


24.1 


P 


9/ 5/28 


14.9 


P 


9/ 7/28 


27.5 


n 


9/ 7/28 


26.0 


n 


9/11/28 


22.8 


P 


9/13/28 


27.2 


n 


9/15/28 


27.8 


Pacific 




n 


10/30/28 


14.4 


n 


11/19/28 


22.4 


r. 


11/19/28 


18.6 


P 


11/19/28 


22.4 


n 


11/21/28 


23.3 


n 


11/21/28 


23.2 


n 


11/21/28 


22.5 


P 


11/21/28 


23.3 


P 


11/21/28 


23.2 


n 


11/23/28 


23.9 


n 


11/23/28 


23.8 


n 


11/23/28 


22.7 


P 


11/23/28 


23.8 


n 


11/27/28 


21.6 



36.5 


8.21 


8 


36.4 


8.20 


19 


36.5 


8.21 


8 


36.4 


8.20 


19 


36.4 


8.23 


8 


36.5 


8.17 


13 


36.6 


8.28 


12 


36.6 


8.29 


9 


37.0 


8.23 


5 


36.8 


8.24 


5 


36.8 


8.24 


5 


36.8 


8.21 


5 


37.1 


8.27 


5 


37.1 


8.27 


5 


36.6 


8.26 


3 


36.6 


8.26 


3 


36.7 


8.19 


5 


36.2 


8.26 


4 


36.8 


8.20 


7 


36.2 


8.21 


9 


36.0 


8.14 


13 


36.0 


8.22 


12 


36.0 


8.22 


12 


35.7 


7.93 


121 


36.1 


8.21 


5 


35.6 


8.11 


40 


36.3 


8.31 


4 


36.2 


8.30 


4 


36.6 


8.22 


7 


36.2 


8.29 


3 


36.1 


8.29 


3 


34.9 


7.85 


149 


35.2 


8.13 


46 


35.1 


8.00 


50 


35.3 


8.12 


38 


35.3 


8.16 


36 


35.3 


8.16 


40 


35.4 


8.17 


40 


35.3 


8.16 


36 


35.3 


8.16 


40 


36.0 


8.23 


17 


36.0 


8.23 


20 


36.2 


8.23 


20 


36.0 


8.23 


20 


35.9 


8.26 


13 



86 STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Table 20. Distributional and environmental records for Gonyaulax pacifica Kofoid- -Continued 



Station 



Sample 



Depth 

(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 

(°C) 



Salinity 
(o/oo) 



pH 



PO4 

mg/m3 











Pacif 


ic — Continued 










49 


281 


50 


r 


P 


11/27/28 


22.6 


36.1 


8.26 


13 


50 


288 


50 


r 


P 


11/29/28 


22.0 


35.9 


8.23 


13 




289 


100 


r 


P 


11/29/28 


20.5 


35.7 


8.22 


13 


51 


295 


100 


r 


n 


12/ 1/28 


20.0 


35.6 


8.22 


17 




297 


50 


r 


P 


12/ 1/28 


20.5 


35.6 


8.22 


17 


52 


300 


50 


r 


n 


12/ 3/28 


20.2 


35.6 


8.20 


8 


53 


304 


50 


oc 


n 


12/ 5/28 


21.2 


35.8 


8.20 


13 




305 


100 


r 


n 


12/ 5/28 


19.9 


35.6 


8.19 


13 


54 


320 


50 


r 


n 


12/14/28 


19.8 


35.4 


8.18 


17 


55 


324 


50 


r 


n 


12/16/28 


18.7 


35.0 


8.18 


12 




325 


100 


r 


n 


12/16/28 


16.7 


34.9 


7.17 


12 


56 


329 


50 


r 


n 


12/18/28 


18.5 


35.1 


8.14 


9 




330 


100 


r 


n 


12/18/28 


16.6 


34.8 


8.11 


12 


64 


396 


100 


r 


n 


1/ 3/29 


15.8 


34.5 


8.10 


32 


65 


409 


50 


r 


P 


1/ 5/29 


16.5 


34.5 


8.10 


25 




410 


100 


r 


p 


1/ 5/29 


14.8 


34.3 


8.10 


34 


66 


412 


100 


r 


n 


1/ 7/29 


17.8 


34.9 


8.12 


21 




415 


100 


r 


p 


1/ 7/29 


17.8 


34.9 


8.12 


21 


76 


469 


100 


r 


n 


2/16/29 


21.2 


35.8 


8.12 


45 


77 


474 


50 


r 


P 


2/18/29 


23.5 


36.0 


8.19 


16 


78 


475 





r 


n 


2/20/29 


24.6 


36.0 


8.17 


32 




476 


50 


r 


n 


2/20/29 


23.8 


36.1 


8.14 


32 




477 


100 


oc 


n 


2/20/29 


21.9 


36.2 


8.14 


34 


79 


483 


100 


r 


n 


2/22/29 


21.8 


36.2 


8.13 


45 




484 





r 


P 


2/22/29 


25.2 


36.0 


8.17 


34 


84 


506 


50 


r 


n 


3/ 4/29 


27.5 


36.4 


8.21 


24 


86 


517 


50 


r 


n 


3/ 9/29 


27.4 


36.2 


8.29 


17 


87 


522 


50 


r 


n 


3/11/29 


26.5 


36.1 


8.26 


20 


88 


527 


50 


r 


n 


3/21/29 


28.4 


35.9 


8.25 


13 


91 


544 


100 


r 


P 


3/27/29 


25.8 


36.0 


8.25 


30 


93 


550 





r 


n 


3/31/29 


28.7 


34.7 


8.30 


28 


95 


563 


50 


r 


n 


4/24/29 


29.3 


34.9 


8.24 


16 


96 


573 


100 


r 


P 


4/26/29 


28.2 


35.7 


8.19 


25 


97 


576 


100 


r 


n 


4/28/29 


27.6 


35.6 


8.15 


25 


100 


597 


100 


r 


n 


5/ 4/29 


27.6 


34.7 


8.22 


12 


101 


604 


50 


r 


n 


5/ 7/29 


26.2 


34.7 


8.24 


8 




605 


100 


oc 


n 


5/ 7/29 


25.2 


35.1 


8.23 


8 


102 


609 





r 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




610 


50 


r 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




611 


100 


r 


n 


5/ 9/29 


25.6 


35.0 


8.23 


8 




612 





r 


P 


5/ 9/29 


25.8 


35.0 


8.24 


8 




614 


100 


r 


P 


5/ 9/29 


25.6 


35.0 


8.23 


8 




613 


50 


r 


P 


5/ 9/29 


25.8 


35.0 


8.24 


8 


103 


616 


50 


oc 


n 


5/11/29 


25.8 


35.2 


8.25 


5 




617 


100 


oc 


n 


5/11/29 


24.8 


35.2 


8.25 


5 


104 


622 


50 


r 


n 


5/13/29 


25.8 


35.2 


8.24 


7 




623 


100 


oc 


n 


5/13/29 


25.3 


35.3 


8.21 


7 




626 


100 


r 


P 


5/13/29 


25.3 


35.3 


8.21 


7 


105 


628 


50 


r 


n 


5/15/29 


26.8 


34.9 


8.23 


5 




629 


100 


r 


n 


5/15/29 


25.2 


35.1 


8.23 


5 


106 


633 





r 


n 


5/17/29 


27.2 


35.0 


8.23 


5 




635 


100 


r 


n 


5/17/29 


27.2 


35.0 


8.23 


5 




634 


50 


r 


n 


5/17/29 


27.0 


35.0 


8.23 


5 




637 


50 


r 


p 


5/17/29 


27.0 


35.0 


8.23 


5 




638 


100 


r 


p 


5/17/29 


25.6 


35.1 


8.23 


5 


107 


641 


100 


oc 


n 


5/19/29 


26.8 


34.9 


8.23 


11 


108 


647 


50 


oc 


n 


5/27/29 


26.8 


35.0 


8.24 


4 




648 


100 


r 


n 


5/27/29 


25.2 


36.0 


8.23 


4 


109 


656 


100 


r 


n 


5/29/29 


19.4 


34.8 


8.18 


5 




658 


50 


r 


P 


5/29/29 


23.1 


35.0 


8.22 


3 




659 


100 


oc 


P 


5/29/29 


19.4 


34.8 


8.18 


5 


110 


663 


100 


r 


n 


5/31/29 


17.9 


34.7 


8.14 


11 




665 


50 


r 


P 


5/31/29 


18.4 


34.8 


8.16 


7 




666 


100 


r 


p 


5/31/29 


17.9 


34.7 


8.14 


11 


113 


681 


50 


r 


n 


6/25/29 


23.8 


34.6 


8.25 


5 




682 


100 


r 


n 


6/25/29 


21.5 


34.7 


8.23 


8 




684 


50 


r 


p 


6/25/29 


23.8 


34.6 


8.25 


5 


132 


798 


50 


r 


n 


9/ 8/29 


17.6 


33.9 


8.33 


13 




801 





r 


p 


9/ 8/29 


21.0 


33.9 


8.34 


15 




799 


100 


r 


n 


9/ 8/29 


14.3 


33.4 


8.30 


16 




802 


100 


oc 


P 


9/ 8/29 


14.3 


33.4 


8.30 


16 




804 





r 


n 


9/ 8/29 


21.0 


33.9 


8.34 


15 


133 


805 


50 


r 


n 


9/10/29 


20.8 


34.7 


8.37 


7 


134 


810 


100 


r 


n 


9/12/29 


18.1 


34.6 


8.34 


6 


135 


821 


50 


r 


n 


9AV29 


21.5 


35.0 


8.37 


5 




822 


100 


r 


n 


9/14/29 


18-7 


34.8 


8.34 


5 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



87 



Table 20. Distributional and environmental records for Gonyaulax pacifica Kofoid- -Concluded 


Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 
(°C) 


Salinity 
(o/oo) 


PH 


PO4 

mg/ra* 










Pacific 


--Concluded 








135 


825 


50 


r 


P 


9/14/29 


21.5 


35.0 


8.37 


5 




826 


100 


r 


p 


9/14/29 


18.7 


34.8 


8.34 


5 


136 


828 


50 


oc 


n 


9/16/29 


21.4 


35.1 


8.39 


3 




829 


100 


oc 


n 


9/16/29 


18.6 


35.0 


8.39 


3 




833 


50 


r 


p 


9/16/29 


21.4 


35.1 


8.39 


3 




834 


100 


r 


p 


9/16/29 


18.6 


35.0 


8.39 


3 


137 


837 


50 


r 


n 


9/18/29 


24.4 


35.1 


8.34 


'-: 




838 


100 


r 


n 


9/18/29 


21.5 


35.1 


8.30 


5 


138 


844 


50 


r 


n 


9/20/29 


25.6 


34.7 


8.30 


3 




845 


100 


r 


n 


9/20/29 


22.2 


34.8 


8.31 


3 




848 


50 


r 


P 


9/20/29 


25.6 


34.7 


8.30 


3 


139 


854 


50 


r 


p 


9/22/29 


25.8 


34.9 


8.31 


G 




855 


100 


r 


P 


9/22/29 


22.4 


35.2 


8.28 


6 


140 


857 


50 


r 


n 


10/ 3/29 


26.9 


35.0 


8.39 


7 




858 


100 


r 


n 


10/ 3/29 


25.5 


35.0 


8.34 


7 


141 


864 





r 


n 


10/ 5/29 


25.9 


35.2 


8.34 


5 




865 


50 


r 


n 


10/ 5/29 


24.8 


35.3 


8.34 


5 




870 


50 


r 


P 


10/ 5/29 


24.8 


35.3 


8,34 


5 




871 


100 


r 


P 


10/ 5/29 


20,0 


35.0 


8.33 


5 


142 


874 


100 


r 


n 


10/ 7/29 


16.6 


34.4 


8.27 


7 




879 


100 


r 


P 


10/ 7/29 


16.6 


34.4 


8.27 


7 


143 


883 


100 


r 


n 


10/ 9/29 


13.8 


34.1 


8.30 


10 


145 


890 





r 


n 


10/13/29 


22.3 


34.6 


8.29 


6 




891 


50 


r 


n 


10/13/29 


18.7 


34.3 


3.34 


6 




892 


100 


r 


n 


10/13/29 


16.0 


34.1 


8.31 


6 




893 





r 


P 


10/13/29 


22.3 


34.6 


8.29 


6 


146 


896 





r 


n 


10/15/29 


22.4 


34.9 


8.37 


6 




897 


50 


r 


n 


10/15/29 


22.4 


34.9 


8.30 


6 




898 


100 


r 


n 


10/15/29 


19.7 


34.3 


8.26 


7 




901 


50 


r 


P 


10/15/29 


22.4 


34.9 


8.30 


6 




902 


100 


r 


P 


10/15/29 


19.7 


34.3 


8.26 


7 


147 


904 


50 


r 


n 


10/17/29 


23.1 


35.3 


8.29 


5 




905 


100 


r 


n 


10/17/29 


19.2 


35.0 


8.29 


5 




909 


100 


r 


P 


10/17/29 


19.2 


35.0 


8.29 


5 


149 


922 


100 


oc 


n 


10/21/29 


20.3 


34.9 


8.38 


6 


150 


930 


50 


oc 


n 


10/23/29 


22.8 


34.8 


8.35 


10 




936 


100 


r 


P 


10/23/29 


19.6 


34.6 


8.32 


11 


151 


938 


50 


r 


n 


10/26/29 


18.3 


34.4 








939 


100 


r 


n 


10/26/29 


12.5 


34.5 








942 


50 


r 


P 


10/26/29 


18.3 


34.4 






152 


945 


50 


r 


n 


10/27/29 


14.2 


34.5 


7.87 


53 




946 


100 


r 


n 


10/27/29 


11.4 


34.7 


7.76 


75 


158 


985 


100 


r 


n 


11/ 8/29 


27.6 


35.9 


8.39 


48 


159 


992 


100 


r 


n 


11/11/29 


28.0 


35.7 


8.37 


23 




Table 21. 


Distributional and environmental records for Gonyaulax fusiformis n.sp. 


Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

(°C) 


Salinity 
(o/oo) 


PH 


P °/ 4 3 

mg/m 










Atl 


antic 










18 


114 





r 


p 


8/17/28 


27.0 


37.0 


8.23 


5 




115 


50 


r 


P 


8/17/28 


22.4 


36.8 


8.24 


5 




117 





r 


n 


8/17/28 


27.0 


37.0 


8.23 


5 




119 


100 


r 


n 


8/17/28 


20.4 


36.8 


8.21 


5 


20 


126 


50 


r 


P 


8/22/28 


25.8 


36.6 


8.26 


3 




127 


100 


r 


p 


8/22/28 


22.6 


36.7 


8.19 


5 




128 





r 


n 


8/22/28 


26.0 


36.6 


8.37 


5 




129 


50 


r 


n 


8/22/28 


25.8 


36.6 


8.26 


3 




130 


100 


r 


n 
Pac 


8/22/28 
if i c 


22.6 


36.7 


8.19 


5 


46 


265 


50 


r 


p 


11/21/28 


23.2 


35.3 


8.16 


40 




267 


50 


r 


n 


11/21/28 


23.2 


35.3 


8.16 


40 


47 


269 





r 


P 


11/23/28 


23.9 


36.0 


8.23 


17 


89 


530 





r 


P 


3/23/29 


28.4 


35.6 


8.25 


21 


91 


542 





r 


P 


3/27/29 


28.7 


35.1 


8.30 


21 




544 


100 


r 


P 


3/27/29 


25.8 


36.0 


8.25 


30 


92 


548 


50 


r 


p 


3/29/29 


28.4 


35.4 


8.29 


28 


99 


589 





r 


n 


5/ 2/29 


27.9 


34.9 


8.21 


12 


105 


630 





r 


P 


5/15/29 


26.9 


34.9 


8.23 


5 




631 


50 


r 


p 


5/15/29 


26.8 


34.9 


8.23 


5 


107 


642 





r 


p 


5/19/29 


28.0 


34.4 


8.23 


5 


109 


656 


100 


r 


n 


5/29/29 


19.4 


34.8 


8.13 


5 



88 



STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PERIDINIALES 



Table 21. Distributional and environmental records for Gonyaulax fusiformis n.sp. --Concluded 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 

(°C) 



Salinity 
(o/oo) 



pH 



PO4 

mg/m3 



133 


805 


50 




813 


50 


135 


822 


100 




825 


50 




826 


100 


136 


832 







834 


100 


137 


840 





138 


845 


100 


139 


854 


50 


149 


927 





154 


959 


50 



Pacific 
n 

P 
n 

P 
P 
P 
P 
P 
n 

P 
P 
n 



--Concluded 




9/10/29 


20.8 


9/10/29 


20.8 


9/14/29 


18.7 


9/14/29 


21.5 


9/14/29 


18.7 


9/16/29 


24.6 


9/16/29 


18.6 


9/18/29 


25.5 


9/20/29 


22.2 


9/22/29 


25.8 


10/21/29 


23.5 


10/31/29 


28.2 



34.7 


8.37 


7 


34.7 


8.37 


7 


34.8 


8.34 


5 


35.0 


8.37 


5 


34.8 


8.34 


5 


35.4 


8.37 


3 


35.0 


8.39 


3 


35.0 


8.39 


4 


34.8 


8.31 


3 


34.9 


8.31 


6 


35.0 


8.34 


6 


34.2 


8.40 


7 



Table 22. Distributional and environmental records for 
Acanthogonyaulax spinifera (Murr. and Whitt.) Graham 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

(°C) 


Salinity 
(0/00) 


pH 


PO4 

mg/m^ 










Pacific 










46 


261 





r 


n 


11/21/28 


23.3 


35.3 


8.16 


36 




262 


50 


r 


n 


11/21/28 


23.2 


35.3 


8.16 


40 




263 


100 


r 


n 


11/21/28 


22.5 


35.4 


8.17 


40 


48 


273 


100 


r 


n 


11/25/28 


22.7 


36.3 


8.26 


16 


79 


481 





r 


n 


2/22/29 


25.2 


36.0 


8.17 


34 




484 





r 


P 


2/22/29 


25.2 


36.0 


8.17 


34 


80 


488 





r 


P 


2/24/29 


26.0 


35.9 


8.20 


36 


81 


491 





r 


n 


2/28/29 


26.5 


35.8 


8.19 


38 




493 





r 


P 


2/26/29 


26.5 


35.8 


8.19 


38 


90 


534 


50 


r 


n 


3/25/29 


28.6 


35.6 


8.26 


21 


100 


596 


50 


r 


n 


5/ 4/29 


27.6 


34.7 


8.21 


10 




597 


100 


oc 


n 


5/ 4/29 


27.6 


34.7 


8.22 


12 




599 


50 


r 


P 


5/ 4/29 


27.6 


34.7 


8.21 


10 


101 


604 


50 


r 


n 


5/ 7/29 


26.2 


34.7 


8.24 


8 




605 


100 


oc 


n 


5/ 7/29 


25.2 


35.1 


8.23 


8 


102 


609 





r 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




610 


50 


r 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 


103 


617 


100 


r 


n 


5/11/29 


24.8 


35.2 


8.25 


5 




620 


100 


r 


P 


5/11/29 


24.8 


35.2 


8.25 


5 


104 


622 


50 


r 


n 


5/13/29 


25.8 


35.2 


8.24 


7 


105 


628 


50 


r 


n 


5/15/29 


26.8 


34.9 


8.23 


5 


107 


639 





r 


n 


5/19/29 


28.0 


34.4 


8.23 


5 


109 


658 


50 


r 


P 


5/29/29 


23.1 


35.0 


8.22 


3 


112 


677 





r 


p 


6/ 5/29 


23.2 


34.6 


8.22 


7 


113 


681 


50 


r 


n 


6/25/29 


23.8 


34.6 


8.25 


5 


136 


829 


100 


r 


n 


9/16/29 


18.6 


35.0 


8.39 


3 


139 


851 


100 


r 


n 


9/22/29 


22.4 


35.2 


8.28 


6 


145 


892 


100 


r 


n 


10/13/29 


16.0 


34.1 


8.31 


6 


146 


898 


100 


r 


n 


10/15/29 


19.7 


34.3 


8.26 


7 


149 


921 


50 


r 


n 


10/21/29 


23.3 


35.0 


8.37 


7 




927 





r 


P 


10/21/29 


23.5 


35.0 


8.34 


7 


159 


991 


50 


r 


n 


11/11/29 


28.5 


35.7 


8.39 


15 



Table 23. Distributional and environmental records for Spiraulax kofoidii new name 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 

(°C) 


Salinity 
(0/00) 


PH 


P ? 4 3 

mg/m° 










Atl 


intic 










1 


1 





r 


n 


5/12/28 


24.0 


36.2 


8.16 


34 


19 


122 





oc 


n 


8/20/28 


26.6 


37.0 


8.34 


5 




123 


50 


r 


n 


8/20/28 


25.2 


37.1 


8.27 


5 




124 


100 


r 


n 


8/20/28 


22.4 


37.0 


8.25 


5 


21 


134 


100 


r 


p 


8/24/28 


21.0 


36.8 


8.20 


7 




137 


100 


r 


n 


8/24/28 


21.0 


36.8 


8.20 


7 


22 


139 





oc 


P 


8/27/28 


26.7 


36.0 


8.26 


8 




143 


50 


r 


n 


8/27/28 


24.5 


36.2 


8.21 


9 




144 


100 


r 


n 


8/27/28 


17.5 


36.1 


7.99 


123 


23 


145 





r 


p 


8/29/28 


27.2 


35.9 


8.25 


4 




149 


50 


oc 


n 


8/29/28 


20.9 


36.0 


8.14 


13 




150 


100 


r 


n 


8/29/28 


16.6 


36.0 


8.18 


75 


24 


152 


50 


r 


P 


8/31/28 


23.1 


36.0 


8.14 


8 



DISTRIBUTIONAL AND ENVIRONMENTAL RECORDS 



89 



Table 23. Distributional and environmental records for Spiraulax kofoidii new name --Continued 



Station 



Sample 



Depth 
(m) 



Relative 
abundance 



Apparatus 



Date 



Temperature 

(°C) 



Salinity 
(o/oo) 



PH 



PO4 

mg/m^ 



24 
25 

26 
27 
29 
31 
32 



44 
45 

46 

47 

48 

49 



49a 
50 



51 



52 
53 

53a 



54 
55 
56 

62 
63 

64 



65 
66 

67 



73 
80 

81 



83 
85 

87 



155 
157 
158 
164 
172 
184 
191 
194 
195 



253 

259 

260 

262 

263 

266 

267 

269 

271 

273 

274 

277 

279 

280 

281 

282 

283 

284 

285 

286 

287 

289 

290 

291 

292 

294 

295 

297 

298 

300 

301 

303 

304 

305 

306 

310 

311 

313 

322 

324 

329 

330 

373 

380 

388 

396 

402 

403 

404 

406 

412 

414 

416 

418 

425 

427 

452 

486 

488 

491 

492 

493 

502 

510 

522 



50 



50 

50 

100 

100 





50 







50 

50 

100 



50 





100 





100 



50 

100 





50 

100 



100 







50 

100 

50 

100 

50 

100 



50 

100 











50 

50 

100 

100 

50 



100 







50 

100 

50 



100 

50 



100 







50 



50 



50 



Atlantic --Concluded 



r 

oc 

oc 

r 

r 

r 

r 

r 

r 



r 

r 

r 

r 

r 

r 

r 

r 

oc 

r 

oc 

r 

r 

r 

r 

r 

oc 

c 

oc 

oc 

oc 

r 

oc 

oc 

oc 

oc 

oc 

r 

r 

r 

oc 

oc 

oc 

oc 

r 

r 

oc 

r 

r 

oc 

r 

oc 

r 

r 

r 

r 

r 

r 

r 

r 

r 

r 

r 

oc 

r 

r 

r 

r 

r 

c 

r 

r 

r 

r 

r 



n 


8/31/28 


23.1 


P 


9/ 3/28 


27.5 


P 


9/ 3/28 


21.5 


P 


9/ 5/28 


24.1 


n 


9/ 7/28 


17.7 


n 


9/13/28 


23.1 


n 


10/ 3/28 


28.5 


n 


10/ 5/28 


28.0 


n 


10/ 5/28 


27.2 


P 


acif ic 




P 


11/17/28 


20.7 


P 


11/19/28 


22.4 


P 


11/19/28 


22.4 


n 


11/21/28 


23.2 


n 


11/21/28 


22.5 


n 


11/23/28 


23.9 


n 


11/23/28 


23.8 


P 


11/23/28 


23.9 


n 


11/25/28 


23.6 


n 


11/25/28 


22.7 


P 


11/25/28 


23.6 


n 


11/27/28 


23.4 


n 


11/27/28 


21.6 


P 


11/27/28 


23.4 


P 


11/27/28 


22.6 


P 


11/27/28 


21.6 


n 


11/28/28 


(23.2) 


n 


11/29/28 


(23.2) 


n 


11/29/28 


22.0 


n 


11/29/28 


20.5 


P 


11/29/28 


23.2 


P 


11/29/28 


20.5 


n 


12/ 1/28 


22.8 


n 


12/ 1/28 


22.8 


n 


12/ 1/28 


22.8 


u 


12/ 1/28 


20.5 


n 


12/ 1/28 


20.0 


P 


12/ 1/28 


20.5 


P 


12/ 1/28 


20.0 


n 


12/ 3/28 


20.2 


n 


12/ 3/28 


18.2 


n 


12/ 5/28 


22.6 


n 


12/ 5/28 


21.2 


n 


12/ 5/28 


19.9 


P 


12/ 5/28 


22.6 


n 


12/10/28 


(23.0; 


n 


12/10/28 


23.0 


n 


12/10/28 


(23.0) 


P 


12/14/28 


23.4 


n 


12/16/28 


18.7 


n 


12/18/28 


18.5 


n 


12/18/28 


16.6 


n 


12/18/28 


13.1 


n 


1/ 1/29 


17.0 


n 


1/ 1/29 


20.5 


n 


1/ 3/29 


15.8 


n 


1/ 3/29 


20.6 


n 


1/ 3/29 


20.6 


n 


1/ 3/29 


20.6 


n 


1/ 5/29 


16.5 


n 


1/ 7/29 


17.8 


P 


1/ 7/29 


17.8 


n 


1/ 8/29 


19.3 


n 


1/ 8/29 


16.2 


n 


1/12/29 


17.4 


P 


1/12/29 


21.1 


n 


2/10/29 


14.7 


n 


2/24/29 


26.0 


P 


2/24/29 


26.0 


n 


2/26/29 


26.5 


n 


2/26/29 


26.4 


P 


2/26/29 


26.5 


n 


3/ 2/29 


27.4 


n 


3/ 6/29 


27.9 


n 


3/11/29 


26.5 



36.0 


8.14 


8 


35.6 


8.31 


5 


36.0 


8.22 


12 


36.1 


8.21 


5 


36.0 


8.09 


46 


36.6 


8.21 


8 


34.4 


8.27 


2 


36.0 


8.23 


2 


36.0 


8.24 


2 


34.9 


8.03 


33 


35.3 


8.12 


38 


35.2 


8.13 


46 


35.3 


8.16 


40 


35.4 


8.17 


40 


36.0 


8.23 


17 


36.0 


8.23 


20 


36.0 


8.23 


17 


36.4 


8.23 


13 


36.3 


8.26 


16 


36.4 


8.23 


13 


36.2 


8.27 


13 


35.9 


8.26 


13 


36.2 


8.27 


13 


36.1 


8.26 


13 


35.9 


8.26 


13 


36.0) 


(8.23) 
(8.23; 


(13) 


'36.0) 


(13) 


35.9 


8.23 


13 


35.7 


8.22 


13 


36.0 


8.23 


13 


35.7 


8.22 


13 


35.6 


8.22 


16 


35.6 


8.22 


16 


35.6 


8.22 


16 


35.6 


8.22 


17 


35.6 


8.22 


17 


35.6 


8.22 


17 


35.6 


8.22 


17 


35.6 


8.20 


8 


35.2 


8.17 


8 


35.7 


8.22 


13 


35.8 


8.20 


13 


35.6 


8.19 


13 


35.7 


8.22 


13 


(35.6) 
35.6) 


(8.22) 


88 


(8.22) 


(35.6) 


(8.22) 


(li) 


35.5 


8.22 


9 


35.0 


8.18 


12 


35.1 


8.14 


9 


34.8 


8.11 


12 


34.2 


8.06 


48 


34.6 


8.08 


25 


34.6 


8.07 


21 


34.5 


8.10 


32 


34.6 


8.12 


21 


34.8 


8.12 


21 


34.6 


8.12 


21 


34.5 


8.10 


25 


34.9 


8.12 


21 


34.8 


8.10 


29 


34.9 


8.11 


21 


34.6 


8.05 


40 


35.1 


7.99 


151 


35.2 


8.12 


62 


35.0 


7.80 


178 


35.9 


8.20 


36 


35.9 


8.20 


36 


35.8 


8.19 


38 


35.9 


8.19 


38 


35.8 


8.19 


38 


36.5 


8.24 


25 


36.2 


8.22 


40 


36.1 


8.26 


20 



90 STUDIES IN THE MORPHOLOGY, TAXONOMY, AND ECOLOGY OF THE PEREDINIALES 



Table 23. Distributional and environmental records for Spiraulax kofoidii new name --Concluded 



Station 


Sample 


Depth 
(m) 


Relative 
abundance 


Apparatus 


Date 


Temperature 
(°C) 


Salinity 
(o/oo) 


PH 


P04„ 

mg/m° 










P acif ic 


--Concluded 








88 


526 





r 


n 


3/21/29 


28.5 


35.9 


8.23 


16 




527 


50 


r 


n 


3/21/29 


28.4 


35.9 


8.25 


13 


89 


532 





r 


n 


3/23/29 


28.4 


35.6 


8.25 


21 


90 


533 





oc 


n 


3/25/29 


28.5 


35.5 


8.27 


21 


91 


540 





oc 


n 


3/27/29 


28.7 


35.1 


8.30 


21 




542 





r 


P 


3/27/29 


28.7 


35.1 


8.30 


21 


92 


545 





c 


n 


3/29/29 


28.5 


35.3 


8.29 


28 


93 


550 





c 


n 


3/31/29 


28.7 


34.7 


8.30 


28 




551 


50 


oc 


n 


3/31/29 


28.5 


34.8 


8.30 


28 


96 


569 


50 


r 


n 


4/26/29 


29.2 


35.3 


8.23 


12 


97 


575 


50 


oc 


n 


4/28/29 


28.0 


35.4 


8.16 


21 


98 


585 


50 


r 


P 


4/30/29 


26.9 


35.3 


8.16 


28 




588 


100 


r 


P 


4/30/29 


26.7 


35.4 


8.14 


32 


99 


589 





r 


n 


5/ 2/29 


27.9 


34.9 


8.21 


12 




590 


50 


r 


n 


5/ 2/29 


27.8 


34.9 


8.22 


12 




591 


100 


oc 


n 


5/ 2/29 


27.8 


35.0 


8.22 


17 




593 


50 


r 


P 


5/ 2/29 


27.8 


34.9 


8.22 


12 




595 





r 


n 


5/ 2/29 


27.9 


34.9 


8.21 


12 


100 


596 


50 


r 


n 


5/ 4/29 


27.6 


34.7 


8.21 


10 




597 


100 


oc 


n 


5/ 4/29 


27.6 


34.7 


8.22 


12 


101 


603 





oc 


n 


5/ 7/29 


26.3 


34.7 


8.24 


8 




604 


50 


oc 


n 


5/ 7/29 


26.2 


34.7 


8.24 


8 




605 


100 


oc 


n 


5/ 7/29 


25.2 


35.1 


8.23 


8 


102 


609 





r 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




610 


50 


oc 


n 


5/ 9/29 


25.8 


35.0 


8.24 


8 




611 


100 


oc 


n 


5/ 9/29 


25.6 


35.0 


8.23 


8 


103 


615 





oc 


n 


5/11/29 


26.0 


35.0 


8.25 


5 




616 


50 


r 


n 


5/11/29 


25.8 


35.2 


8.25 


5 


104 


621 





r 


n 


5/13/29 


26.1 


35.2 


8.24 


7 




623 


100 


oc 


n 


5/13/29 


25.3 


35.3 


8.21 


7 


105 


628 


50 


r 


n 


5/15/29 


26.8 


34.9 


8.23 


5 


106 


638 


100 


r 


P 


5/17/29 


25.6 


35.1 


8.23 


5 


107 


639 





r 


n 


5/19/29 


28.0 


34.4 


8.23 


5 




640 


50 


r 


n 


5/19/29 


27.9 


34.4 


8.23 


4 


108 


648 


100 


r 


n 


5/27/29 


25.2 


35.0 


8.23 


4 


109 


654 





r 


n 


5/29/29 


27.4 


35.0 


8.23 


3 




656 


100 


r 


n 


5/29/29 


19.4 


34.8 


8.18 


5 


110 


663 


100 


r 


n 


5/31/29 


17.9 


34.7 


8.14 


11 


130 


787 





oc 


n 


9/ 4/29 


16.2 


33.4 


8.34 


36 


132 


792 





r 


n 


9/ 9/29 


21.0 


33.9 


8.34 


15 




798 


50 


r 


n 


9/ 9/29 


17.6 


33.9 


8.33 


19 




799 


100 


r 


n 


9/ 9/29 


14.3 


33.4 


8.30 


16 




803 


100 


r 


P 


9/ 9/29 


14.3 


33.4 


8.30 


16 


138 


843 





r 


n 


9/20/29 


26.1 


34.8 


8.35 


5 




845 


100 


r 


n 


9/20/29 


22.2 


34.8 


8.31 


3 


139 


851 


100 


r 


n 


9/22/29 


22.4 


35.2 


8.28 


6 


140 


860 





r 


P 


10/ 3/29 


26.9 


35.0 


8.42 


7 




857 


50 


r 


n 


10/ 3/29 


26.9 


35.0 


8.39 


7 




858 


100 


r 


n 


10/ 3/29 


25.5 


35.0 


8.34 


7 




861 


50 


r 


P 


10/ 3/29 


26.9 


35.0 


8.39 


7 




863 


100 


r 


P 


10/ 3/29 


25.5 


35.0 


8.34 


7 


141 


864 





r 


n 


10/ 5/29 


25.9 


35.2 


8.34 


5 




868 





r 


P 


10/ 5/29 


25.9 


35.2 


8.34 


5 


142 


873 


50 


r 


n 


10/ 7/29 


21.8 


34.8 


8.30 


5 




874 


100 


r 


n 


10/ 7/29 


16.6 


34.4 


8.27 


7 




877 


50 


r 


P 


10/ 7/29 


21.8 


34.8 


8.30 


5 


143 


882 


50 


r 


n 


10/ 9/29 


19.0 


34.2 


8.34 


6 


145 


891 


50 


oc 


n 


10/13/29 


18.7 


34.3 


8.34 


6 




892 


100 


r 


n 


10/13/29 


16.0 


34.1 


8.31 


6 


146 


901 


50 


r 


p 


10/15/29 


22.4 


34.9 


8.30 


6 


149 


921 


50 


r 


n 


10/21/29 


23.3 


35.0 


8.37 


6 


150 


929 





r 


n 


10/23/29 


25.6 


34.7 


8.39 


7 




931 


100 


oc 


n 


10/23/29 


19.6 


34.6 


8.32 


11 




933 





r 


P 


10/23/29 


25.6 


34.7 


8.39 


7 




936 


100 


r 


P 


10/23/29 


19.6 


34.6 


8.32 


11 


152 


944 





r 


n 


10/27/29 


27.4 


33.7 


8.35 


20 


153 


951 





r 


n 


10/29/29 


28.1 


34.2 


8.47 


7 


154 


959 


50 


r 


n 


10/31/29 


28.2 


34.2 


8.40 


7 


155 


965 





r 


n 


11/ 2/29 


27.8 


34.9 


8.29 


29 


157 


978 





r 


n 


11/ 6/29 


27.1 


35.3 


8.27 


47 


158 


983 





T 


n 


11/ 8/29 


28.2 


35.6 


8.34 


36 




984 


50 


r 


n 


11/ 8/29 


28.2 


35.6 


8.39 


50 




985 


100 


r 


n 


11/ 8/29 


27.6 


35.9 


8.39 


48 


159 


992 


100 


r 


n 


11/11/29 


28.0 


35.7 


8.37 


23 


160 


1002 


50 


r 


n 


11/13/29 


28.6 


35.6 


8.39 


15 



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physoidae, marine armored dinoflagellates, of Monte- 
rey Bay, California. Arch. f. Protistenk., vol. 82, pp. 
380-482, 14 text figs., pis. 11, 12. 

Vanhoffen, E. 1897a. Die Fauna und Flora Gronlands. 

Gronland Expedition der Gesellschaft fur Erdkunde zu 
Berlin, vol. 2, pp. 254-320, pis. 3-6, map 10. 

1897b. Botanische Ergebnisse der Gesellschaft fur 

Erdkunde zu Berlin, unter Leitung Dr. von Drygalski 
ausgesandten Gronlands Expedition nach Dr. Vanhoffen's 
Sammlungen bearbeitet. A, Kryptogamen, IE, Peridi- 
neen und Dinobryeen. Bibl. Bot., vol. 8, pp. 25-27, pi. 1.. 

Wang, C. C, and D. Nie. 1932. A survey of the marine 
protozoa of Amoy. Contr. Biol. Lab. Sci. Soc. China, 
vol. 7, pp. 285-385, 89 text figs. 
Whedon, W. F., and C. A. Kofoid, 1936. Dinoflagellata of 
the San Francisco region. I: On the skeletal morphol- 
ogy of two new species, Gonyaulax catenella and G. 
acatenella . Univ. Calif. Publ., Zool., vol. 41, pp. 25- 
34, 16 text figs. 
Wilson, C. B. 1942. The copepods of the plankton gathered 
during the last cruise of the Carnegie. Sci. Res. of 
Cruise VII of the Carnegie during 1928-29 under the 
command of Captain J. P. Ault, Biol. I. Carnegie Inst. 
Wash. Pub. No. 536, 237 pp., 136 figs. 
Woloszynska, J. 1916. Polinische Suswasser-Peridineen. 
Bull. Acad. sci. Cracovie, ser. B, CI. d. sci. math. u. 
nat. (1915), pp. 265-281. 



FIGURES 1 - 67 



PLATE I 



FIGURES 1-9 

Fig. 1. Comparison of tabulations of ventral areas of various genera of the Peridini- 
ales. A, primitive area; B, Ceratocorys horrida; C, Goniodoma polyedricum ; D, Gonyaulax 
pacifica ; E, Gonyaula x fusiformis ; F, Acanthogonyaulax spinifera ; G, Spiraulax kofoidii ; H, 
Peridinium crassipes . (For explanation, see pp. 7-8.) 

Fig. 2. Diagram illustrating concepts of relationships of genera treated in this report. 

Fig. 3. A, diagram of cross section of thecal wall of Peridinium in region of suture, 
simple suture without intercalary zone; B, hypothetical diagram of same following development 
of intercalary zone. External intercalary zone observed; internal intercalary zone not yet 
demonstrated. 

Fig. 4. Examples of the three types of first apical plates. A, Orthoperidinium ; B, 
Metaperidinium ; C, Paraperidinium . 

Fig. 5. Examples of the three types of dorsal epithecal tabulation used by Jorgensen, 
Paulsen, et al. in subdividing the subgenera of Peridinium . (See text for explanation.) 

Fig. 6. Epithecal tabulation. A, with three intercalary plates; B, with only two inter- 
calary plates. 

Fig. 7. Diagram showing the dimensions used in the study of body proportions in 
Peridinium . Ventral view. 

Fig. 8. Diagram showing the dimensions used in the study of body proportions in 
Peridinium . Apical view. 

Fig. 9. Epithecal plate patterns in the section Oceanica . A, first symmetrical; B, 
second symmetrical; C, first asymmetrical; D, second asymmetrical; E, intergrade between 
first symmetrical and first asymmetrical. 



96 



A 

ra 


as 

p 


A 

Is 


rs 


/ ps 




FIGURES 10-18 

Fig. 10. Frequency distribution of the x-ratios in 144 random specimens related to 
P. depressum Bailey. O , P. depression; x, P. oceanicum ; • , var. parallelum ; ■ , var. 
tenellum. 

Fig. 11. Frequency distribution of length classes in 170 random specimens related to 
P. depressum . 

Fig. 12. Frequency distribution of the diameter classes in 170 random specimens 
related to P. d epressum. 

Fig. 13. Frequency distribution of the h/d classes in 170 random specimens related 
to P. depressum . 

Fig. 14. Peridinium depressum Bailey. A, in "resting" position in bottom of drop of 
mounting medium; B, ventral view; C, left side view; D, apical view; E, dorsal view; F, 
antapical view. Magnification: x 170. 

Fig. 15. Apex of P. depressum Bailey. A, intact; B, plates separated. Symbols: ap, 
apical pore; app, apical pore platelet: apl-ap4, first to fourth apical plates; dl, dorsal seg- 
ment of apical list; lal, left segment of apical list; 111, left lateral list; ral, right segment of 
apical list; rll, right lateral list; vap, ventral apical platelet. Magnification: x 670. 

Fig. 16. Girdle of P. depressum Bailey. A, intact. Symbols: iz, intercalary zone; 
s, sulcus; lg-4g, first to fourth girdle plates. B, section showing strengthening ridges. C, 
cross section showing attachment to adjacent plate and cingular list. Symbols: bp, body plate; 
cl, cingular list; g, girdle plate. Magnification: A, X 230; B and C, x 470. 

Fig. 17. Ventral area of P. depi essum Bailey. A, ventral view intact; B, left ventral 
view intact, membranes not shown; C, ventral view showing plates separated. Magnification: 
x 400. Symbols: acl, anterior cingular list; ag. anterior flagellar groove; agl, anterior groove 
list; antl, first antapical plate; ant2, second antapical plate; apl, first apical plate; app, ante- 
rior pore process; arl, anterior right sulcal list; as, anterior sulcal plate; iz, intercalary 
zone; 11, left sulcal list; Is, left sulcal plate; m, membrane; p, flagellar pore; pas, posterior 
accessory sulcal plate; pel, posterior cingular list; pg, posterior flagellar groove; pgl, poste- 
rior groove list; pi, posterior sulcal list; pol, first postcingular plate; po5, fifth postcingular 
plate; ppp, posterior pore process; prl, first precingular plate; pr7, seventh precingular 
plate; prl, posterior right sulcal list; ps, posterior sulcal plate; ras, right accessory sulcal 
list; ris, right internal sulcal plate; rs, right sulcal plate; lg, 2g, 4g, first, second, anri 
fourth girdle plates. 

Fig. 18. Details of ventral area. A, left side view with left sulcal plate removed; B, 
same with plates separated; C, posterior view of cross section of posterior end of sulcus; D, 
anterior view of cross section of right sulcal plate. Magnification: A and B, x 730; C and D, 
x 400. (Symbols as in fig. 17.) 



98 




99 



FIGURES 19 and 20-A 

Fig. 19. Variations in body form in P. depressum Bailey. Magnification: x 230. 
Fig. 20-A. Distribution of species of Peridinium at Carnegie stations. 



100 





101 



FIGURES 20-B, 20-C, and 20-D 

Fig. 20-B. Distribution of species of Peridinium at Carnegie stations. 
Fig. 20-C. Distribution of species of Peridinium at Carnegie stations. 
Fig. 20-D. Distribution of species of Peridinium at Carnegie stations. 



102 




103 



FIGURES 21 - 29 

Fig. 21. Peridinium depressum var. parallelum Broch. A, "resting" position; B, 
ventral view; C, right side view; D, apical view. Magnification: x 230. 

Fig. 22. Ventral views of four specimens of P. depressum var. parallelum Broch. 
Magnification: x 230. 

Fig. 23. Frequency distribution of a. classes in 108 random specimens of P. depressum 
Bailey and var. parallelum Broch. 

Fig. 24. Frequency distribution of a/d classes in 108 random specimens of P. depres - 
sum Bailey and var. parallelum Broch. 

Fig. 25. Peridinium depressum var. rectius n.var. A, apical view; B, right side view; 
C, ventral view. Magnification: x 230. Type specimen from station 32. 

Fig. 26. Peridinium depressum var. convexius n.var. A, C, apical and ventral views 
of type specimen from station 14; B, ventral view of specimen from station 16; D, ventral 
view of specimen from station lb. Magnification: x 230. 

Fig. 27. Peridinium depressum f. bisintercalares n.f. A, B, ventral views of two 
specimens; C, apical view of A; D, apical view of B. Magnification: x 230. A, C, type 
specimen from station 13. 

Fig. 28. Peridinium depressum f . multitabulatum n.f. A, ventral view; B, apical view. 
Magnification: x 230. Type specimen. 

Fig. 29. Peridinium claudicanoides n.sp. A-C, ventral, right side, and apical views of 
same specimen; D-F, ventral, left side, and apical views of a second specimen; G, H, ventral 
views of two other specimens. Magnification: x 230. A-C, type specimen from station 2 (S. 14); 
D-F, from station 3 (S.19); H, from station 2 (S. 14); G, from station 1-A (S. 5). 



104 






: l0 s 

" U 


80 








90° 







• 

« 


o 
• 




• 
o 

a 


10° 120° 130° 
a CLASSES 

SPECIMENS WHERE 
















o a 




" • 


• 




• 




h/d<l.20 




-So 























• 









- cr 










* 





• 


• 






• 


■ ■ 


• 




- m 

■ D 


• 


• 


• 


• 


• • 





• 


« e 




a 


• 


* o 


11 a . FIG ' 23 


- 





20 0-16 0.28 0.40 0.52 

di/d CLASSES 





105 



FIGURES 30-36 

Fig. 30. Peridinium oceanicum Vanhoffen. A, in "resting" position in bottom of drop 
of mounting medium; B, apical view; C, ventral view; D, right side view. Magnification: x 230. 

Fig. 31. Frequency distribution of length classes in 82 random specimens of P. oceani - 
cum and its variants. 

Fig. 32. Peridinium oceanicum var. tenellum n.var. A, apical view; B, right side 
view; C, ventral view. Magnification: x 230. Type specimen. 

Fig. 33. Variations in body shape in P. oceanicum var. tenellum n.var. Magnifica- 
tion: x 230. 

Fig. 34. A, B, C, ventral views of three specimens of P. oceanicum f. spiniferum n.f.; 
D, apical view of A; E, apical view of C. Magnification: x 230. A, D, from station 13 (S. 85); 
B, from station 13 (S. 86); C, E, from station 13 (S. 85). 

Fig. 35. Peridinium oceanicum f. bisintercalares n.f. A, apical view; B, ventral view. 
Magnification: x 230. Type specimen. 

Fig. 36. Peridinium oceanicum f. tricornutum n.f. A, ventral view; B, antapical view. 
Magnification: x 230. 



106 



FIGURES 37, 38-A, and 38-B 

Fig. 37. P_e_ ridinium crassipes Kofoid from station 99 (sample 590). A, apical view; 
B, ventral view; C, antapical view; D, apical view of separated girdle plates; E, ventral view 
of separated sulcal plates; F, ventral view of undissected sulcal complex; rabbet membranes 
not shown; G, right lateral view. Magnification: x 340. Symbols: as, anterior sulcal plate; 
gl-g4, first to fourth girdle plates; la, left accessory sulcal list; lal, left segment of apical 
list; Is, left sulcal plate; p, flagellar pore; pas, posterior accessory sulcal plate; ps, poste- 
rior sulcal plate; ral, right segment of apical list; ras, right accessory sulcal list; ris, 
right internal sulcal plate; rl, right sulcal list; rll, right lateral list; rs, right sulcal plate. 

Fig. 38-A. Distribution of Peridinium crassipes and Peridinium pallidum at 
Carnegie stations. 

Fig. 38-B. Distribution of Peridinium truncatum at Carnegie stations. 



108 





109 



FIGURES 39-42 

Fig. 39. Peridinium truncatum n.sp. A, apical view of specimen from station 35 
showing epithecal plate pattern and cross ribs in anterior cingular list; B, antapical view of 
same with sulcal elements labeled; C, dissection of apex; D, dissection of ventral area and 
adjacent plates; E, ventral view of specimen shown in A; F, left lateral view of separated 
right sulcal plate showing internal processes and right accessory sulcal list; G, separated 
girdle plates; cross ribs on outer surface of girdle plates indicated for only small part of one 
plate; H, right lateral view of specimen shown in A. Magnification: x 340. Symbols: a, 
anterior internal sulcal process; antl, ant2, first and second antapical plates; apl-ap4, first 
to fourth apical plates; as, anterior sulcal plate; dl, dorsal segment of apical list; gl-g4, 
first to fourth girdle plates; lal, left segment of apical list; la, left accessory sulcal list; 
11, left sulcal list; Is, left sulcal plate; p, posterior internal sulcal process; pas, posterior 
accessory sulcal plate; pal, posterior accessory sulcal list; pi, posterior sulcal list; pol, 
po5, first and fifth postcingular plates; pp, apical pore platelet; prl, pr7, first and seventh 
precingular plates; ps, posterior sulcal plate; ral, right segment of apical list; ras, right 
accessory sulcal list; rs, right sulcal plate; vp, ventral apical platelet. Type specimen. 

Fig. 40. A, B, Peridinium truncatum n.sp. A, apical view of specimen with intercalary 
zones from station 91; B, ventral view of same. C, D, Peridinium truncatum forma acutum, n.f.; 
C, ventral view; D, apical view of same. Magnification: x 230. C, D, type specimen, from 
station 104. 

Fig. 41. Ventral area and adjacent regions in P. truncatum n.sp. Magnification: x 270. 
(Cf. figs. 39D, E.) 

Fig. 42. Peridinium pallidum Ost. A, ventral view of specimen from station 13; B, 
apical view of same; C, antapical view of same; D, dorsal view of same; E, right lateral view 
of same; F, apical view of separated girdle plates; G, detail of distal end of girdle; H, dissec- 
tion of ventral area and adjacent plates. Magnification: A-F, x 340; G, H, x 770. Symbols: 
all, anterior segment of left sulcal list; antl, ant2, first and second antapical plates; apl, first 
apical plate; arl, anterior segment of right sulcal list; app, apical pore platelet; as, anterior 
sulcal plate; dl, dorsal segment of apical list; gl-g4, first to fourth girdle plates; i, inter- 
calary zone; lal, left segment of apical list; 111, left lateral list; Is, left sulcal plate; pas, 
posterior accessory sulcal plate; pi, posterior sulcal list; pll, posterior segment of left sul- 
cal list; pol, po5, first and fifth postcingular plates; prl, posterior segment of right sulcal 
list; prl, pr7, first and seventh precingular plates; ps, posterior sulcal plate; ra, right 
accessory sulcal plate; ral, right segment of apical list; ras, right accessory sulcal list; rll, 
right lateral list; rs, right sulcal plate; vap, ventral apical platelet; l'-4', first to fourth 
apical plates; la, 3a, first and third anterior intercalary plates; 1", 6", first and sixth pre- 
cingular plates. 



110 





... 






• 




111 



FIGURES 43-46 

Fig. 43, Peridinium pallidum Ost. A, anteroventral view of apex; B, latero-poste- 
roventral view of ventral area and adjacent regions; C, diagram of same; D, diagram of A. 
Magnification: A, D, x 810; B, C, x 660. (For symbols, see fig. 42.) 

Fig. 44. Skeletal dissection of Ceratocorys horrida Stein. A, in ventral view; B, in 
apical view. Symbols: al, a2, first and second anterior intercalary plate; ac, anterior 
cingular list; ant, antapical plate; apl, ap2, first and second apical plate; as, anterior sulcal 
plate; ep, ventral epithecal pore; gl, g2, g5, g6, first, second, fifth, and sixth girdle plates; 
Is, left sulcal plate; pc, posterior cingular plate; pi, posterior intercalary plate; pi, apical 
pore platelet; pol-po3, po6, first to third, and sixth postcingular plates; prl-pr5, first to 
fifth precingular plates; ps, posterior sulcal plate; ra, right accessory sulcal plate; rs, 
right sulcal plate; vb, ventral body list; vs, ventral spine. 

Fig. 45. Diagram of the dimensions used in the study of body proportions in 
Ceratocorys . (See p. 36 for explanation.) 

Fig. 46. Graphical representation of the relationships of the species of Ceratocorys . 



112 




113 



FIGURES 47-51 

Fig. 47. Typical mature Ceratocorys horrida Stein, from station 57. A, antapical 
view; B, ventral view; C, apical view; D, left lateral view; E, right lateral view. Magnifi- 
cation: x 340. 

Fig. 48. Daughter cells of Ceratocorys horrida Stein. A, B, C, D, apical, antapical, 
left lateral, and ventral views, respectively, of left (two-spined) daughter cell with old left 
moiety and new right moiety, from sample 192; E, F, G, apical, right lateral, and ventral 
views, respectively, of right (four-spined) daughter cell with old right moiety and new left 
moiety, from sample 335; H, left daughter cell with directly opposed spines, from sample 
256; I, left daughter cell with rather dependent spines, from sample 284. Magnification: 
x 230. 

Fig. 49. Ceratocorys horrida Stein. A, long-spined form from sample 278; B, thick- 
walled, heavily sculptured form from sample 161; C, long-spined form with double dorsal and 
ventral spines, from sample 272; D, short-spined form with dorsal spine absent, from sam- 
ple 161; E, anterior view of sixth girdle plate showing the partitioning lists on the girdle; F, 
short-spined form (hypotheca only) with double dorsal and ventral spines, from sample 240; 
G, long-spined form, from sample 1; H, short-spined form showing autotomy of the spines; 
three of the antapical spines have been cast off; the other spines are fracturing; I, J, K, cross 
sections of bases of dorsal, right, and ventral spines, respectively. Magnification: x 230; 
except B, x 340. 

Fig. 50. Thin-walled, spineless specimen of Ceratocorys horrida Stein from sample 
284. A, ventral view; B, apical view; surface of pr2-pr4 not shown; C, right lateral view, 
surface not shown. Magnification: x 340. 

Fig. 51. Frequency distribution of length of spine in C. horrida . 



114 




115 



FIGURES 52-A, 52-B, and 52-C 

Fig. 52-A. Distribution of species of Ceratocorys at Carnegie stations. 
Fig. 52-B. Distribution of species of Ceratocorys at Carnegie stations. 
Fig. 52-C. Distribution of species of Ceratocorys at Carnegie stations. 



116 




117 



FIGURES 53 - 56, and 58 

Fig. 53. Ceratocorys armata (Schutt) Kofoid. A, ventral view of specimen from sam- 
ple 271; B, apical view of same; C, apical view of left daughter cell from sample 287; D, 
right lateral view of specimen in A; E, antapex of same. Magnification: x 460. 

Fig. 54. Ceratocorys armata (Schutt) Kofoid. A, heavy-walled specimen from sample 
13, ventral view; B, antapex of same; C, anterior view of a girdle plate showing the heavy, 
well -developed transverse lists or ridges of the girdle; D, antapex of specimen from sample 
99 showing approximation of the left and dorsal antapical spines; E, specimen from sample 
290 with unusually long spines; left antapical spine absent. Magnification: x 340. 

Fig. 55. Ceratocorys reticulata n.sp. A, ventral view; B, apical view; C, right 
lateral view; D, antapical view. Magnification: x 380. Type specimen, from sample 177. 

Fig. 56. Ceratocorys aultii n.sp. A, ventral view; B, antapical view; C, apical view; 
D, right lateral view. Sutures indicated by dotted lines. Magnification: X 520. Type speci- 
men, from sample 337. 

Fig. 58. Ceratocorys skogsbergii n.sp. A, ventral view; B, apical view; C, antapical 
view; D, right lateral view. Magnification: x 570. Type specimen, from sample 291. 



118 




119 



FIGURES 57, 59, and 60 

Fig. 57. Ceratocorys bipes (Cleve) Kofoid. A, ventral view of specimen from sample 
273; B, apical view of same; C, right lateral view of specimen with abortive spines from sam- 
ple 257; D, right lateral view of specimen shown in A; E, antapical view of same; F, right 
lateral view of specimen from sample 330. Magnification: x 520. 

Fig. 59. Ceratocorys gourretii Paulsen. A, ventral view of specimen from sample 
157; B, apical view of same; C, antapical view of same; D, right lateral view of same show- 
ing autotomy of dorsal spine; E, left daughter cell from sample 265; F, left lateral view of 
specimen from sample 402 showing double ventral spine; G, left daughter cell from sample 
287; H, fourth postcingular plate from old moiety of specimen shown in E, showing large 
intercalary zone with scattered pits. Magnification: A-D, x 470; E, G, H, x 340; F, x 290. 

Fig. 60. Goniodoma polyedricum Pouchet. A, apical view of specimen from station 
45; arrows indicate position of girdle sutures; heavy lines indicate position of epithecal 
sutures; B, antapical view of same; optical section of girdle is shown at fourth postcingular 
plate only; C, separated precingular plate of heavily sculptured specimen; rabbet membranes 
indicated; D, separated first precingular showing ventral epithecal pore; E, section of girdle 
to show excavation; F, undissected sulcal complex; G, separated sulcal elements; H, ventral 
view of specimen shown in A; I, right view of same. Magnification: x 340. Symbols: as, 
anterior sulcal plate; Is, left sulcal plate; m, rabbet membrane; ps, posterior sulcal plate; 
ra, right accessory sulcal plate; rs, right sulcal plate. 



120 




121 



FIGURES 61-A, 61-B, and 61-C 

Fig. 61-A. Distribution of species of Gonyaulax and Acanthogonyaulax at Carnegie 
stations. 

Fig. 61-B. Distribution of species of Goniodoma at Carnegie stations. 

Fig. 61-C. Distribution of species of Spiraulax at Carnegie stations. 



122 




123 



FIGURES 61 -D, 62, and 63 

Fig. 61-D. Distribution of species of Gonyaulax at Carnegie stations. 

Fig. 62. Gonyaulax pacifica Kofoid. A, ventrolateral view of specimen, from station 
45; B, cross section of girdle; C, ventrolateral view showing sutures only; D, apical view of 
same; E, antapical view of specimen from station 22; F, apical view of separated girdle 
plates; G, antapical view of specimen shown in A; H, true ventral view of specimen from 
station 49; I, right lateral view of specimen shown in A; J, left lateral view of same; K, ven- 
tral view of undissected ventral area; L, ventral view of separated sulcal and adjacent plates. 
Magnification: x 340. Symbols: al, a2, first and second anterior intercalary plates; ant, 
antapical plate; apl-ap3, first to third apical plates; ar, anterior segment of right sulcal 
list; as, anterior sulcal plate; gl-g6, first to sixth girdle plates; i, intercalary sulcal plate; 
11, left sulcal list; Is, left sulcal plate; pas, posterior accessory sulcal plate; pol-po6, first 
to sixth postcingular plates; prl-pr6, first to sixth precingular plates; ps, posterior sulcal 
plate; ra, right accessory sulcal plate; rs, right sulcal plate; vp, ventral epithecal pore. 

Fig. 63. Gonyaulax fusiformis n.sp. A, reconstruction of apical view, arrows indi- 
cate position of girdle sutures; B, diagram of plate pattern in apical view; C, diagram of 
the ventral area undissected; three plates also shown separately in their broadest aspect; D, 
ventral view of specimen from station 18; E, ventral view of another specimen from the same 
sample; F, antapical view of»same specimen; G, right lateral view of same specimen partial- 
ly dissected, showing inside surface of the second apical plate. Magnification: x 520. Sym- 
bols: al, a2, first and second anterior intercalary plates; ac, anterior cingular list; ant, 
antapical plate; apl-ap3, first to third apical plates; as, anterior sulcal plate; g4-g6, fourth 
to sixth girdle plates; i, intercalary sulcal plate; 11, left sulcal list; Is, left sulcal plate; p f 
flagellar pore; pc, posterior cingular list; pi, posterior intercalary plate; pol-po6, first to 
sixth postcingular plates; pp, anterior pore platelet; prl-pr6, first to sixth precingular 
plates; ps, posterior sulcal plate; ra, right accessory sulcal plate; rl, right sulcal list; rs, 
right sulcal plate; sp, sulcal spine; va, ventral area; vp, ventral epithecal pore; x, limb of 
second apical plate; y, limb of third apical plate. E, F, G, type specimen. 



124 



FIGURES 64-67, and PLATES I-A, I-B, and I-C 

Fig. 64. Acanthogonyaulax spinifera (Murray and Whitting) Graham. A, separated 
plates of the ventral area and adjacent regions; B, ventral view of specimen from station 48; 
C, antapical view of specimen from station 46; D, diagram of undissected ventral area and 
first three precingular plates; E, apical view of specimen shown in C; arrows indicate posi- 
tions of girdle sutures. Magnification: x 470. Symbols: apl-ap3, first to third apical plates; 
as, anterior sulcal plate; i, intercalary sulcal plate; la, left accessory sulcal plate; Is, left 
sulcal plate; p, flagellar pore; pi, posterior intercalary plate; pol, po2, po6, first, second 
arid sixth postcingular plates; prl-pr4, pr8, pr9, first to fourth, eighth, and ninth precingular 
plates; ps, posterior sulcal plate; ra, right accessory sulcal plate; rs, right sulcal plate; 
vp, ventral epithecal pore. 

Fig. 65. Acanthogonyaulax spinifera (Murray and Whitting) Graham. Ventral view 
of specimen from station 48. Magnification: x 470. 

Fig. 66. Spiraulax kofoidii new name. A, diagram of ventral area undissected; B, 
separated sulcal plates presenting their broadest aspects; sculpturing not shown on ps; C, 
right lateral view of entire specimen from station 48; D, antapical view of same; E, apical 
view of same; arrows indicate position of girdle sutures; F, antapical view of sixth girdle 
plate showing the membrane which lies against the cingular list; G, ventral view of specimen 
shown in C. Magnification: x 340. Symbols: a, anterior intercalary plate; ant, antapical 
plate; apl-ap4, first to fourth apical plates; as, anterior sulcal plate; gl-g6, first to sixth 
girdle plates; i, intercalary sulcal plate; 11, left sulcal list; Is, left sulcal plate; p, flagellar 
pore; pi, posterior intercalary plate; m, rabbet membrane; pc, posterior cingular list; pol- 
po6, first, to sixth postcingular plates; prl-pr6, first to sixth precingular plates; ps, posterior 
sulcal plate; ra, right accessory sulcal plate; rl, right sulcal list; rs, right sulcal plate; va, 
ventral area. 

Fig. 67. Ceratium pavillardii Jorgensen from station 67. A, apical view of right side 
of body at level of girdle showing end of posterior girdle list, curvature of body at lateral mar- 
gin, and curvature of horn trough; B, apical platelet; C, ventral view of entire specimen; D, 
third girdle plate in apical view; E, antapical view of fourth girdle plate; F, distal end of 
third girdle plate; G, ventral view of body; plates of ventral area not indicated; body pores 
shown on only part of body; H, dorsal view of body; only few body pores shown; I, four plates 
of ventral area. Magnification: C, x 50; other figures x 340. 

Plate I-A. Details of skeletal structure of P. depressum . Ventral area and adjacent 
regions. Magnification: x 400. (Cf. fig. 17.) 

Plate I-B. Details of skeletal structure of P. depressum . Detail of ventral area. 
Magnification: x 730. (Cf. fig. 18.) 

Plate I-C. Details of skeletal structure of P. depressum . Detail of apex. Magnifica- 
tion: x 670. (Cf. fig. 15.) 



126 




470 FIG. 64 





P' X340 







I 



~\ 



. 




127 



INDEX 



Abstract, 1 

Acanthogonyaulax, 8, 52 
Acanthogonyaulax spinifera, 53 
acutum, Peridinium truncatum, f., 32 
armata, Ceratocorys, 40 
aultii, Ceratocorys, 42 

bipes, Ceratocorys, 43 

bisintercalares, Peridinium depressum, forma, 23 

bisintercalares, Peridinium oceanicum, f., 26 

Ceratiaceae, 56 
Ceratium, 8, 56 

pavillardii, 56 
Ceratocoryaceae, 34 
Ceratocorys, 8, 34, 38 

armata, 40 

aultii, 42 

bipes, 43 

gourretii, 44 

horrida, 38 

reticulata, 42 

skogsbergii, 44 
claudicanoides, Peridinium, 24 
convexius, Peridinium depressum, var., 23 
crassipes, Peridinium, 27 

depressum forma bisintercalares, Peridinium, 23 

forma multitabulatum, Peridinium, 23 

Peridinium, 15 

var. convexius, Peridinium, 23 

var. parallelum, Peridinium, 21 

var. rectius, Peridinium, 22 
Dissection of specimens, 3 

Epitheca, 9 
Euceratocorys, 38 

Families of Peridiniales, key, 4 
Forms treated, list, 6 
fusiformis, Gonyaulax, 50 

Genera: 

plate formulas, 5 

plate abbreviations, 5 
Girdle, 9 

Goniodomaceae, 45 
Goniodoma, 45 

polyedricum, 46 
Gonyaulacaceae, 47 
Gonyaulax, 8, 47 

fusiformis, 50 

pacifica, 48 
gourretii, Ceratocorys, 44 

horrida, Ceratocorys, 38 
Hypotheca, 9 



Introduction, 2 

kofoidii, Spiraulax, 55 

multitabulatum, Peridinium depressum, forma, 23 

Oceanica, key, 27 

oceanicum, f. bisintercalares, Peridinium, 26 

f. spiniferum, Peridinium, 26 

f. tricornutum, Peridinium, 27 

Peridinium, 24 

var. tenellum, Peridinium, 25 

pacifica, Gonyaulax, 48 

pallidum, Peridinium, 32 

parallelum, Peridinium depressum, var., 21 

pavillardii, Ceratium, 56 

Peridiniaceae, 11 

Peridiniales, key to families, 4 

Peridinium, 8, 11 

claudicanoides, 24 

crassipes, 27 

depressum, 15 

depressum forma bisintercalares, 23 

depressum forma multitabulatum, 23 

depressum var. convexius, 23 

depressum var. parallelum, 21 

depressum var. rectius, 22 

oceanicum f. bisintercalares, 26 

oceanicum f. spiniferum, 26 

oceanicum f. tricornutum, 27 

oceanicum, 24 

oceanicum var. tenellum, 25 

pallidum, 32 

truncatum, 30 

truncatum f. acutum, 32 
polyedricum, Goniodoma, 46 
Protoceratocorys, 43 

rectius, Peridinium depressum, var., 22 
reticulata, Ceratocorys, 42 

skogsbergii, Ceratocorys, 44 
Species, key, 38 
Specimens, dissection, 3 
spinifera, Acanthogonyaulax, 53 
spiniferum, Peridinium oceanicum, f., 26 
Spiraulax, 54 

kofoidii, 55 
Sulcal plates, 7 

Tables, 59 

tenellum, Peridinium oceanicum, var., 25 
tricornutum, Peridinium oceanicum, f., 27 
truncatum, f. acutum Peridinium, 32 
truncatum, Peridinium, 30 

Ventral area, 7 



129